@article{mohammadbagherpoor_acemoglu_mattos_caldwell_johnson_muth_grant_2022, title={Designing and Testing a Closed-Loop Magnetically Actuated Laser Scanning System for Tissue Ablation}, volume={16}, ISSN={["1932-619X"]}, DOI={10.1115/1.4053073}, abstractNote={Abstract Biomedical robotic systems continue to hold unlimited potential for surgical procedures. Robotized laser endoscopic tools provide surgeons with increased accuracy in the laser ablation of tissue and tumors. The research here catalogs the design and implementation of a new laser endoscopic tool for tissue ablation. A novel feature of this new device is the inclusion of a feedback loop that measures the position of the laser beam via a photo-detector sensor. The scale of this new device was governed by the dimensions of the photo-detector sensor. The tip of the laser's fiber optic cable is controlled by the torque interaction between permanent magnet rings surrounding the fiber optic and the custom designed solenoid coils. Prior to building the physical test-bed the system was modeled and simulated using COMSOL software. In pre-clinical trials, the physical experimental results showed that the designed prototype laser scanner system accurately track different ablation patterns and gives a consistent output position for the laser beam however, the heat diffusion into the tissue around the desired line of the geometric shape would give wider ablation margins than was desirable.}, number={2}, journal={JOURNAL OF MEDICAL DEVICES-TRANSACTIONS OF THE ASME}, author={Mohammadbagherpoor, Hamed and Acemoglu, Alperen and Mattos, Leonardo S. and Caldwell, Darwin and Johnson, James J. and Muth, John and Grant, Edward}, year={2022}, month={Jun} }
 @misc{mattos_acemoglu_geraldes_laborai_schoob_tamadazte_davies_wacogne_pieralli_barbalata_et al._2021, title={mu RALP and Beyond: Micro-Technologies and Systems for Robot-Assisted Endoscopic Laser Microsurgery}, volume={8}, ISSN={["2296-9144"]}, DOI={10.3389/frobt.2021.664655}, abstractNote={Laser microsurgery is the current gold standard surgical technique for the treatment of selected diseases in delicate organs such as the larynx. However, the operations require large surgical expertise and dexterity, and face significant limitations imposed by available technology, such as the requirement for direct line of sight to the surgical field, restricted access, and direct manual control of the surgical instruments. To change this status quo, the European project μRALP pioneered research towards a complete redesign of current laser microsurgery systems, focusing on the development of robotic micro-technologies to enable endoscopic operations. This has fostered awareness and interest in this field, which presents a unique set of needs, requirements and constraints, leading to research and technological developments beyond μRALP and its research consortium. This paper reviews the achievements and key contributions of such research, providing an overview of the current state of the art in robot-assisted endoscopic laser microsurgery. The primary target application considered is phonomicrosurgery, which is a representative use case involving highly challenging microsurgical techniques for the treatment of glottic diseases. The paper starts by presenting the motivations and rationale for endoscopic laser microsurgery, which leads to the introduction of robotics as an enabling technology for improved surgical field accessibility, visualization and management. Then, research goals, achievements, and current state of different technologies that can build-up to an effective robotic system for endoscopic laser microsurgery are presented. This includes research in micro-robotic laser steering, flexible robotic endoscopes, augmented imaging, assistive surgeon-robot interfaces, and cognitive surgical systems. Innovations in each of these areas are shown to provide sizable progress towards more precise, safer and higher quality endoscopic laser microsurgeries. Yet, major impact is really expected from the full integration of such individual contributions into a complete clinical surgical robotic system, as illustrated in the end of this paper with a description of preliminary cadaver trials conducted with the integrated μRALP system. Overall, the contribution of this paper lays in outlining the current state of the art and open challenges in the area of robot-assisted endoscopic laser microsurgery, which has important clinical applications even beyond laryngology.}, journal={FRONTIERS IN ROBOTICS AND AI}, author={Mattos, Leonardo S. and Acemoglu, Alperen and Geraldes, Andre and Laborai, Andrea and Schoob, Andreas and Tamadazte, Brahim and Davies, Brian and Wacogne, Bruno and Pieralli, Christian and Barbalata, Corina and et al.}, year={2021}, month={Sep} }
 @article{mohammadbagherpoor_ierymenko_craver_carlson_dausch_grant_lucey_2020, title={An Implantable Wireless Inductive Sensor System Designed to Monitor Prosthesis Motion in Total Joint Replacement Surgery}, volume={67}, ISSN={["1558-2531"]}, DOI={10.1109/TBME.2019.2943808}, abstractNote={Currently, the most common method for detecting prosthetic implant loosening is imaging. Unfortunately, imaging methods are imprecise in detecting the early signs of implant loosening. This paper describes a new wireless inductive proximity sensor system for detecting early implant loosening. The loosening of the implant is accurately detected by analyzing the electromagnetic field generated by the passive sensors located around the implant. The sensor system was modeled and simulated using COMSOL, and then tested experimentally. The inductive proximity sensor and the metallic implant form a coupled circuit is tuned to oscillate at a designed frequency. The circuit's integrated controller measures and records specific sensor's parameters such as resistance and inductance of the sensor that are directly related to the distance between the sensor system and the implant. A prototype has been developed and the results show that the designed proximity sensor is capable of measuring the loosening of the hip implant at 50 μm resolution at distances of less than 8 mm, and of 100 μm resolution at a distance of 15 mm. Furthermore, there is a good correlation between the simulated and experimental results.}, number={6}, journal={IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING}, author={Mohammadbagherpoor, Hamed and Ierymenko, Paul and Craver, Meghan H. and Carlson, Jim and Dausch, David and Grant, Edward and Lucey, John D.}, year={2020}, month={Jun}, pages={1718–1726} }
 @article{kwon_hegarty_oxenham_thoney-barletta_grant_reid_2019, title={An introduction to a new direct testing method for characterizing pressure in compression fabrics}, volume={110}, ISSN={["1754-2340"]}, DOI={10.1080/00405000.2018.1527966}, abstractNote={A newly developed direct pressure measuring system known as the CRIM Pressure System was compared with a traditional direct measuring device, the PicoPress Compression System, for compression banda...}, number={6}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Kwon, Cassandra and Hegarty, Meghan and Oxenham, William and Thoney-Barletta, Kristin and Grant, Edward and Reid, Lawrence}, year={2019}, month={Jun}, pages={822–831} }
 @article{kwon_hegarty_oxenham_thoney-barletta_grant_reid_2018, title={An indirect testing approach for characterizing pressure profiles of compression bandages and hosiery}, volume={109}, ISSN={["1754-2340"]}, DOI={10.1080/00405000.2017.1340079}, abstractNote={AbstractAs outlined in compression therapy literature, the performance of a compression textile can be characterized by its stiffness and interface pressure. In this study, an indirect approach for measuring pressure from a set of compression bandages and hosiery was developed, from which rigidity (EI) values were determined, and tension–elongation curves and pressure-elongation data were calculated. The calculated pressure values were compared against PicoPress sensor readings measured on 10 participants. Results showed that the correlation between both approaches varied among bandage and hosiery samples.}, number={2}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, publisher={Informa UK Limited}, author={Kwon, Cassandra and Hegarty, Meghan and Oxenham, William and Thoney-Barletta, Kristin and Grant, Edward and Reid, Lawrence}, year={2018}, pages={256–267} }
 @article{deshpande_grant_henderson_draelos_2016, title={Autonomous navigation using received signal strength and bearing-only pseudogradient interpolation}, volume={75}, ISSN={["1872-793X"]}, DOI={10.1016/j.robot.2015.10.009}, abstractNote={Autonomous mobile robots (AMRs) interacting with an a priori distributed wireless sensor network (WSN) in a region can address the three-tier challenge of navigating in unknown environments: (i) identifying target locations, (ii) planning paths to the targets, and (iii) efficiently executing the navigation paths to the targets. This paper presents low-complexity algorithms to address the second-tier and third-tier challenges, i.e., efficiently planning and executing paths to target locations. These novel approaches use only the information inherent in WSNs, i.e., received signal strength (RSS). The objective is to have the AMR navigate to a target location by: (i) producing an RSS-based artificial magnitude distribution in the navigation region, (ii) using particle filtering based bearing estimation for orientation information, and (iii) using interpolated pseudogradient for efficient path planning and navigation. Here, the AMR does not require: (i) the global location information for itself or the WSN, (ii) a priori information of the direction of a target location, or (iii) sophisticated ranging equipment for prior mapping. The AMR relies only on local, neighborhood information and low-cost wireless directional antennas for navigation. Real-world and simulation experiments, using a variety of node-densities, demonstrate the effectiveness of the proposed schemes. The low-cost, low-complexity advantages of the WSN-AMR interactive navigation provide for efficient map-less and ranging-less navigation methods. Efficient WSN-assisted AMR navigation by only 1 modality, received signal strength.Novel use of standard artificial potential field for way-point estimation.Introducing implicit surfaces for inter-node pseudogradient interpolation in WSN.Novel use of standard particle filtering for RSS-based WSN-node bearing estimation.Extensive simulation and hardware experimental validation.}, journal={ROBOTICS AND AUTONOMOUS SYSTEMS}, author={Deshpande, Nikhil and Grant, Edward and Henderson, Thomas C. and Draelos, Mark T.}, year={2016}, month={Jan}, pages={129–144} }
 @misc{hegarty-craver_grant_kravitz_reid_2016, title={Response to critique on methods for studying the pressure applied by compression fabrics}, volume={25}, ISSN={["2062-2916"]}, DOI={10.12968/jowc.2016.25.sup4.s26}, number={4}, journal={JOURNAL OF WOUND CARE}, author={Hegarty-Craver, M. and Grant, Edward and Kravitz, S. and Reid, L.}, year={2016}, month={Apr}, pages={S26–S27} }
 @misc{permana_grant_walker_yoder_2016, title={Review of Automated Microinjection Systems for Single Cells in the Embryogenesis Stage}, volume={21}, ISSN={["1941-014X"]}, DOI={10.1109/tmech.2016.2574871}, abstractNote={Modern genetics research has resulted in significant advances in cell in vitro microinjection systems. Such systems provide biological and medical practitioners with high volume cell throughput and statistically relevant data. This paper provides the reader with a comprehensive review of the major research technologies used in automated cell microinjection and of their individual subsystems. Microinjection subsystems reviewed include machine vision, nonvision sensors and user interface (input), cell modeling, piercing mechanisms and injection control loop (control), cell holder and manipulator, and microinjection (output). The interdisciplinary technologies reviewed for microinjection sensing, automation, and control include microfluidic actuation, optical field actuation (optical trapping and optical guidance), electrical field actuation (electrorotation, electrowetting, and dielectrophoresis), and ultrasonic vibration. The survey concludes that research into automated microinjection systems will focus on reducing the scale of microinjection systems and developing appropriate controllers.}, number={5}, journal={IEEE-ASME TRANSACTIONS ON MECHATRONICS}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Permana, Sofie and Grant, Edward and Walker, Glenn M. and Yoder, Jeffrey A.}, year={2016}, month={Oct}, pages={2391–2404} }
 @inproceedings{hegarty-craver_grant_reid_2015, title={A Wearable bioimpedance spectroscopy system for characterizing fluid distribution in the lower limbs}, DOI={10.1109/mfi.2015.7295829}, abstractNote={Compression therapy is used to treat and manage many vascular conditions. Unfortunately, the mechanism by which compression affects the body has remained largely uncharacterized because there are no wearable systems for continuously assessing blood flow and swelling. In this study, a wearable bioimpedance spectroscopy system was designed to measure changes in limb impedance. This system applied stimuli at frequencies ranging from 10–100 kHz while maintaining a constant current level. During controlled laboratory and wear tests, the system was found to be capable of resolving small changes in impedance. The newly designed system was an improvement over similar portable bioimpedance systems because it was smaller, consumed less power, and could select between a range of frequencies to study different physiological information.}, booktitle={2015 IEEE International Conference on Multisensor Fusion and Integration for Intelligent Systems (MFI)}, author={Hegarty-Craver, M. and Grant, E. and Reid, L.}, year={2015}, pages={328–333} }
 @inproceedings{grant_livingston_craver_hegarty-craver_mcmaster_2015, title={Characterizing conductive yarns for pressure sensors applications}, booktitle={2015 ieee sensors}, author={Grant, E. and Livingston, F. and Craver, M. and Hegarty-Craver, M. and McMaster, S.}, year={2015}, pages={108–111} }
 @article{gulati_king_gill_pham_grant_duddalwar_2015, title={Contrast-enhanced ultrasound (CEUS) of cystic and solid renal lesions: a review}, volume={40}, ISSN={0942-8925 1432-0509}, url={http://dx.doi.org/10.1007/S00261-015-0348-5}, DOI={10.1007/S00261-015-0348-5}, number={6}, journal={Abdominal Imaging}, publisher={Springer Science and Business Media LLC}, author={Gulati, Mittul and King, Kevin G. and Gill, Inderbir S. and Pham, Vivian and Grant, Edward and Duddalwar, Vinay A.}, year={2015}, month={Jan}, pages={1982–1996} }
 @inproceedings{craver_grant_2015, title={Design and implementation of a sensorimotor network for chemical sensing using a mobile robot platform}, DOI={10.1109/mfi.2015.7295806}, abstractNote={Many current robotic systems are application-specific and have difficulty if the environment changes. These controllers do not scale well with increased task complexity, and rely on widely used high quality sensors. However, biological systems exhibit impressive adaptability. Therefore, self-organizing architectures should be incorporated into robotic systems to allow for emergent intelligence and robustness given less than optimal sensors and environments. In this study, a flat, fully-connected sensorimotor architecture was implemented on the EvBot III platform for the application of chemical sensing. The network was trained to associate increased alcohol concentration with increased battery charge. Seven training and testing experiments were conducted using different learning protocols. Although the sensorimotor network was shown to be a good initial step towards robotic reflex behavior, the robot was unable to successfully learn to home to the alcohol source.}, booktitle={2015 IEEE International Conference on Multisensor Fusion and Integration for Intelligent Systems (MFI)}, author={Craver, M. and Grant, E.}, year={2015}, pages={184–189} }
 @article{king_gulati_malhi_hwang_gill_cheng_grant_duddalwar_2015, title={Quantitative assessment of solid renal masses by contrast-enhanced ultrasound with time–intensity curves: how we do it}, volume={40}, ISSN={0942-8925 1432-0509}, url={http://dx.doi.org/10.1007/S00261-015-0468-Y}, DOI={10.1007/S00261-015-0468-Y}, number={7}, journal={Abdominal Imaging}, publisher={Springer Science and Business Media LLC}, author={King, Kevin G. and Gulati, Mittul and Malhi, Harshawn and Hwang, Darryl and Gill, Inderbir S. and Cheng, Phillip M. and Grant, Edward G. and Duddalwar, Vinay A.}, year={2015}, month={Jun}, pages={2461–2471} }
 @article{hegarty-craver_kwon_oxenham_grant_reid_2015, title={Towards characterizing the pressure profiles of medical compression hosiery: an investigation of current measurement devices and techniques}, volume={106}, ISSN={["1754-2340"]}, DOI={10.1080/00405000.2014.941535}, abstractNote={Medical compression hosiery is prescribed according to the pressure it applies to a limb. There are many devices available for measuring this pressure, but differences in the design of the systems used, measurement locations, protocols, and operators result in different pressures being measured for the same garment. This article explores the construction of these compression-measuring devices and the sensing involved in order to highlight the potential causes of these discrepancies. The Tension–Elongation profiles of six compression hosiery samples were then measured, and a method of verifying the point pressure measurements from current techniques was proposed and tested. The results of this analysis show that there was an average discrepancy of 1–5 mmHg between point pressure measurements and those predicted from the Tension–Elongation profiles. With respect to on-body measurements, this technique predicted a maximum change in pressure of 3 mmHg for the samples tested.}, number={7}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Hegarty-Craver, Meghan and Kwon, Cassandra and Oxenham, William and Grant, Edward and Reid, Lawrence, Jr.}, year={2015}, month={Jul}, pages={757–767} }
 @article{suh_carroll_grant_oxenham_2014, title={Investigation into Feasibility of Inductively Coupled Antenna for Smart Clothing}, volume={26}, ISSN={0955-6222}, url={http://dx.doi.org/10.1108/IJCST-10-2012-0064}, DOI={10.1108/ijcst-10-2012-0064}, abstractNote={Purpose – This research investigated the feasibility of using an inductively coupled antenna as the basis of applying a systems approach to smart clothing. In order to simulate real-life situations, the impact of the distortions and relative displacement of different fabric layers (with affixed antennas) on the signal quality was assessed. The paper aims to discuss these issues. Design/methodology/approach – A spiral antenna was printed on different fabric substrates. Obstructive conditions of the inductively coupled fabric layers were investigated to find out how much influence these conditions had on transmission performance. Reflected signals and transmitted signals were observed, while fabric antennas were subjected to displacement (distance and dislocation) or deformation (stretching and bending). The threshold of physical obstacles was estimated based on statistical analyses. Findings – The limits of physical conditions that enable proper wireless transmission were estimated up to ∼2 cm for both distance and dislocation, and ∼0.24 K for bending deformation. The antenna performance remained within an acceptable level of 20 percent transmission up to 10 percent fabric stretch. Based on well-established performance metrics used in clothing environment on the body, which employs 2-5 cm of ease, the results imply that the inductively coupled antennas may be suitable for use in smart clothing. Originality/value – This research demonstrates that the use of inductively coupled antennas on multiple clothing layers could offer the basis of a new “wireless” system approach to smart clothing. This would not only result in performance benefits, but would also significantly improve the aesthetics of smart clothing which should result in new markets for such products.}, number={1}, journal={International Journal of Clothing Science and Technology}, publisher={Emerald}, author={Suh, M. and Carroll, K. and Grant, E. and Oxenham, W.}, year={2014}, pages={25–37} }
 @article{henderson_joshi_rashkeev_boonsirisumpun_luthy_grant_2014, title={Model accuracy assessment in reaction-diffusion pattern formation in wireless sensor networks}, volume={10}, number={4}, journal={International Journal of Unconventional Computing}, author={Henderson, T. C. and Joshi, A. and Rashkeev, K. and Boonsirisumpun, N. and Luthy, K. and Grant, E.}, year={2014}, pages={317–338} }
 @inproceedings{wang_henderson_joshi_grant_2014, title={SLAMBOT: Structural health monitoring robot using lamb waves}, DOI={10.1109/mfi.2014.6997700}, abstractNote={We propose the combination of a mobile robot and a computational sensor network approach to perform structural health monitoring of structures. The robot is equipped with piezoelectric sensor actuators capable of sending and receiving ultrasound signals, and explores the surface of a structure to be monitored. A computational model of ultrasound propagation through the material is used to define two structural health monitoring methods: (1) a time reversal damage imaging (TRDI) process, and (2) a damage range sensor (DRS) (i.e., it provides the range to damaged areas in the structure). The damage in the structure is mapped using the DRS approach.}, booktitle={Processing of 2014 International Conference on Multisensor Fusion and Information Integration for Intelligent Systems (MFI)}, author={Wang, W. Y. and Henderson, T. C. and Joshi, A. and Grant, E.}, year={2014} }
 @article{deshpande_grant_henderson_2014, title={Target Localization and Autonomous Navigation Using Wireless Sensor Networks-A Pseudogradient Algorithm Approach}, volume={8}, ISSN={["1937-9234"]}, DOI={10.1109/jsyst.2013.2260631}, abstractNote={Autonomous mobile robots (AMRs) operating in unknown environments face twin challenges: 1) localization and 2) efficient directed navigation. This paper describes a two-tiered approach to solving these challenges: 1) by developing novel wireless-sensor-network (WSN)-based localization methods and 2) by using WSN-AMR interaction for navigation. The goal is to have an AMR travel from any point within a WSN-covered region to an identified target location without the aid of global sensing and position information. In this research, the target is reached as follows: 1) by producing a magnitude distribution within the WSN region that has a target-directed pseudogradient (PG) and 2) by having the WSN efficiently navigate the AMRs using the PG. This approach utilizes only the topology of the network and the received signal strength (RSS) among the sensor nodes to create the PG. This research shows that, even in the absence of global positioning information, AMRs can successfully navigate toward a target location using only the RSS in their local neighborhood to compute an optimal path. The utility of the proposed scheme is proved through extensive simulation and hardware experiments.}, number={1}, journal={IEEE SYSTEMS JOURNAL}, author={Deshpande, Nikhil and Grant, Edward and Henderson, Thomas C.}, year={2014}, month={Mar}, pages={93–103} }
 @article{m._carroll_grant_oxenham_2013, title={Effect of Fabric Substrate and Coating Material on the Quality of Conductive Printing}, volume={104}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405000.2012.714107}, DOI={10.1080/00405000.2012.714107}, abstractNote={This paper reports an investigation into the effect of fabric substrates and coating materials on the electrical and mechanical performance of printed antennas. Inductively coupled antennas were printed on fabrics using silver ink. To assure printability and protection, a printing structure was configured, consisting of surface coating, conductive printing, and protective coating. In order to simulate a realistic situation, three fabric substrates (denim, broadcloth, and single jersey) were selected from woven and knit fabrics for everyday wear. Three coating materials (acrylic, polyurethane, and silicone) were chosen from conventional conformal coating materials for printed circuit boards. Experimental results verified that fabric substrates can be selected to fit specific end-use application since it is shown that antenna performance was not significantly affected. Silicone coating is suggested to support antenna performance since this gave the least impairment in the fabrics as mechanical performance.}, number={2}, journal={Journal of Textile Institute}, publisher={Informa UK Limited}, author={M., Suh and Carroll, K. and Grant, E. and Oxenham, W.}, year={2013}, pages={213–222} }
 @article{luthy_grant_deshpande_henderson_2012, title={Perimeter detection in wireless sensor networks}, volume={60}, ISSN={0921-8890}, url={http://dx.doi.org/10.1016/j.robot.2011.10.004}, DOI={10.1016/j.robot.2011.10.004}, abstractNote={For a mobile robotic agent to bridge the gaps between disconnected networks, it is beneficial for the robot to first determine the network coverage boundary. Several techniques have been introduced to determine the boundary nodes of a network, but the correctness of these techniques is often ill-defined. We present a technique for obtaining boundary node ground truth from region adjacency analysis of a model-based image created from a network graph. The resulting ground truth baseline is then used for quantitative comparison of several boundary detection methods including a local application of the image region adjacency analysis and the computation of the local convex hull with the addition of a perturbation value to overcome small boundary concavities in the node location point set. Given our proposed metrics of the techniques evaluated, the perturbed convex hull technique demonstrates a high success rate for boundary node identification, particularly when the convex hull is formed using two-hop neighborhoods. This technique was successfully implemented on a physical 25-node network, and the performance of this network implementation is evaluated.}, number={2}, journal={Robotics and Autonomous Systems}, publisher={Elsevier BV}, author={Luthy, Kyle and Grant, Edward and Deshpande, Nikhil and Henderson, Thomas C.}, year={2012}, month={Feb}, pages={266–277} }
 @inproceedings{deshpande_grant_henderson_2012, title={Target-directed navigation using wireless sensor networks and implicit surface interpolation}, DOI={10.1109/icra.2012.6224997}, abstractNote={This paper extends the novel research for event localization and target-directed navigation using a deployed wireless sensor network (WSN) [4]. The goal is to have an autonomous mobile robot (AMR) navigate to a target-location by: (i) producing an artificial magnitude distribution within the WSN-covered region, and (ii) having the AMR use the pseudo-gradient from the interpolated distribution in its neighborhood, as it moves towards the target location. Implicit surfaces are used to interpolate the artificial distribution. This scheme only uses the topology of the WSN and received signal strength (RSS) to estimate an efficient navigation path for the AMR. Here, the AMR does not require global coordinates for the region, as it relies on local, neighborhood information alone to navigate. The performance of the scheme is analyzed with hardware experiments and in simulation, using a variety of node-densities and with increasing levels of noise to ensure robustness.}, booktitle={2012 IEEE International Conference on Robotics and Automation (ICRA)}, author={Deshpande, N. and Grant, E. and Henderson, T. C.}, year={2012}, pages={457–462} }
 @article{hegarty_grant_reid_2010, title={An Overview of Technologies Related to Care for Venous Leg Ulcers}, volume={14}, ISSN={["1558-0032"]}, DOI={10.1109/titb.2009.2036009}, abstractNote={Venous leg ulcers remain a major problem in the United States, with spending reaching more than $1 billion annually. Current treatment options for this condition center around the use of compression therapy delivered by bandages, medical-grade stockings, or pneumatic compression devices. While these forms of therapy can produce dramatic improvements, cost and patient compliance remain an issue. In parallel with this need, wearable, wireless health monitoring systems have recently emerged as a low-cost solution for management of chronic health conditions. To this end, researchers at the Center for Robotics and Intelligent Machines (North Carolina State University) and the Carolon Company (Rural Hall, NC) have proposed an integrated sensing and therapeutic compression module. This article will review technologies related to the design of such a device, as well as provide direction for future research.}, number={2}, journal={IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE}, author={Hegarty, Meghan Sarah and Grant, Edward and Reid, Lawrence, Jr.}, year={2010}, month={Mar}, pages={387–393} }
 @article{mattos_grant_thresher_kluckman_2009, title={Blastocyst Microinjection Automation}, volume={13}, ISSN={["1558-0032"]}, DOI={10.1109/TITB.2009.2023664}, abstractNote={Blastocyst microinjections are routinely involved in the process of creating genetically modified mice for biomedical research, but their efficiency is highly dependent on the skills of the operators. As a consequence, much time and resources are required for training microinjection personnel. This situation has been aggravated by the rapid growth of genetic research, which has increased the demand for mutant animals. Therefore, increased productivity and efficiency in this area are highly desired. Here, we pursue these goals through the automation of a previously developed teleoperated blastocyst microinjection system. This included the design of a new system setup to facilitate automation, the definition of rules for automatic microinjections, the implementation of video processing algorithms to extract feedback information from microscope images, and the creation of control algorithms for process automation. Experimentation conducted with this new system and operator assistance during the cells delivery phase demonstrated a 75% microinjection success rate. In addition, implantation of the successfully injected blastocysts resulted in a 53% birth rate and a 20% yield of chimeras. These results proved that the developed system was capable of automatic blastocyst penetration and retraction, demonstrating the success of major steps toward full process automation.}, number={5}, journal={IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE}, author={Mattos, Leonardo S. and Grant, Edward and Thresher, Randy and Kluckman, Kimberly}, year={2009}, month={Sep}, pages={822–831} }
 @article{merritt_nagle_grant_2009, title={Fabric-Based Active Electrode Design and Fabrication for Health Monitoring Clothing}, volume={13}, ISSN={["1089-7771"]}, DOI={10.1109/TITB.2009.2012408}, abstractNote={<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, two versions of fabric-based active electrodes are presented to provide a wearable solution for ECG monitoring clothing. The first version of active electrode involved direct attachment of surface-mountable components to a textile screen-printed circuit using polymer thick film techniques. The second version involved attaching a much smaller, thinner, and less obtrusive interposer containing the active electrode circuitry to a simplified textile circuit. These designs explored techniques for electronic textile interconnection, chip attachment to textiles, and packaging of circuits on textiles for durability. The results from ECG tests indicate that the performance of each active electrode is comparable to commercial Ag/AgCl electrodes. The interposer-based active electrodes survived a five-cycle washing test while maintaining good signal integrity. </para>}, number={2}, journal={IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE}, author={Merritt, Carey R. and Nagle, H. Troy and Grant, Edward}, year={2009}, month={Mar}, pages={274–280} }
 @article{karaguzel_merritt_kang_wilson_nagle_grant_pourdeyhimi_2009, title={Flexible, durable printed electrical circuits}, volume={100}, ISSN={["1754-2340"]}, DOI={10.1080/00405000802390147}, abstractNote={This study investigates the screen printing of transmission lines into a variety of nonwoven substrates using different conductive inks for durable and wearable electronic textile applications. The viscosity of the ink dictated the performance of the printed media during washing trials. The printed inks begin to degrade and display lower conductivity after 25 wash cycles. A method to control the durability of the printed circuits, which includes coating of the printed lines with a meltblown layer, has been developed.}, number={1}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Karaguzel, B. and Merritt, C. R. and Kang, T. and Wilson, J. M. and Nagle, H. T. and Grant, E. and Pourdeyhimi, B.}, year={2009}, pages={1–9} }
 @article{merritt_nagle_grant_2009, title={Textile-Based Capacitive Sensors for Respiration Monitoring}, volume={9}, ISSN={["1530-437X"]}, DOI={10.1109/JSEN.2008.2010356}, abstractNote={Respiration monitoring in everyday life enables the early detection of the diseases and disorders that can suddenly manifest in a life threatening episode. Long-term monitoring can extend the capabilities of healthcare providers if reliability can be achieved economically. In this paper, the potential for using capacitive sensing to serve as an inexpensive method for long-term respiration sensing is explored. This paper proposes new designs of capacitive sensors for respiration sensing and describes the design and fabrication of a prototype textile-based capacitive-sensor respiration belt. Two capacitive sensors were designed and fabricated for detecting chest or abdominal circumference changes of up to 60 mm. These sensors gave good linearity, and the respiration measurements obtained with these new sensors show that they are capable of measuring respiration rate, and possibly lung function parameters.}, number={1-2}, journal={IEEE SENSORS JOURNAL}, author={Merritt, Carey R. and Nagle, H. Troy and Grant, Edward}, year={2009}, pages={71–78} }
 @article{shankam_oxenham_seyam_grant_hodge_2009, title={Wireless yarn tension measurement, and control in direct cabling process}, volume={100}, ISSN={["0040-5000"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70449397531&partnerID=MN8TOARS}, DOI={10.1080/00405000701830318}, abstractNote={An online yarn tension sensing and control device has been designed and developed. The system was specifically devised for use in a direct cabling machine, wherein yarn tension in the spindle or pot yarn is highly critical and dictates the uniformity of the cabled yarn. Since a balloon formed by the creel yarn always encompasses the pot yarn in a direct cabling machine, yarn tension measurement using a wired sensor is far-fetched. Accordingly, a wireless yarn tension sensor was developed to address this problem and perform online yarn tension measurement. The wireless sensor can be used as an active monitoring tool for measuring online yarn tension in both component yarns, while the closed loop control system replaces passive yarn brakes used in the current direct cabling machines and executes a control mechanism that can control yarn tension adaptively. The device uses Micro-Electro-Mechanical Systems (MEMS) technology with radio frequency (RF) transmission to effectively carry out dynamic online measurement. The control system in conjunction with the wireless sensor ensures equal tension in the component yarns, resulting in the formation of a uniform cabled yarn with equal lengths of both yarns.}, number={5}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Shankam, V. P. and Oxenham, W. and Seyam, A. M. and Grant, E. and Hodge, G.}, year={2009}, month={Jul}, pages={400–411} }
 @article{kang_merritt_grant_pourdeyhimi_nagle_2008, title={Nonwoven fabric active electrodes for biopotential measurement during normal daily activity}, volume={55}, DOI={10.1109/TBME.2007.910678}, abstractNote={Body movement is responsible for most of the interference during physiological data acquisition during normal daily activities. In this paper, we introduce nonwoven fabric active electrodes that provide the comfort required for clothing while robustly recording physiological data in the presence of body movement. The nonwoven fabric active electrodes were designed and fabricated using both hand- and screen-printing thick-film techniques. Nonstretchable nonwoven (Evolon 100) was chosen as the flexible fabric substrate and a silver filled polymer ink (Creative Materials CMI 112-15) was used to form a transducer layer and conductive lines on the nonwoven fabrics. These nonwoven fabric active electrodes can be easily integrated into clothing for wearable health monitoring applications. Test results indicate that nonwoven textile-based sensors show considerable promise for physiological data acquisition in wearable healthcare monitoring applications.}, number={1}, journal={IEEE Transactions on Biomedical Engineering}, author={Kang, T. H. and Merritt, C. R. and Grant, E. and Pourdeyhimi, B. and Nagle, H Troy}, year={2008}, pages={188–195} }
 @article{karaguzel_merritt_kang_wilson_nagle_grant_pourdeyhimi_2008, title={Utility of nonwovens in the production of integrated electrical circuits via printing conductive inks}, volume={99}, ISSN={["1754-2340"]}, DOI={10.1080/00405000701547748}, abstractNote={Abstract This study reports on the printing of conductive inks directly onto nonwovens to produce circuits and embedded systems. The approach adopted applies polymer thick film (PTF) processing technologies directly onto compliant, flexible, nonwoven substrates. The paper reports on the characterization of various PTF conductive inks and printed transmission lines. The performance metrics related to the circuits are impacted by the ink viscosity and by the contact angle of the ink on the surface of the nonwoven structure. These parameters dictate the manner in which the ink is distributed onto and into the substrate. The manner in which ink droplets interact with the surface of the substrate determines the mechanisms responsible for both in-plane flow and through-the-plane flow of the ink.}, number={1}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Karaguzel, B. and Merritt, C. R. and Kang, T. and Wilson, J. M. and Nagle, H. T. and Grant, E. and Pourdeyhimi, B.}, year={2008}, pages={37–45} }
 @article{lee_seyam_hodge_oxenham_grant_2008, title={Warp breaks detection in Jacquard weaving using MEMS: Effect of weave on break signals}, volume={3}, number={1}, journal={Journal of Engineered Fibers and Fabrics}, author={Lee, J. H. and Seyam, A. M. and Hodge, G. and Oxenham, W. and Grant, E.}, year={2008}, pages={25–31} }
 @article{seyam_lee_hodge_oxenham_grant_2007, title={Prevention of warp breaks in Jacquard weaving}, volume={8}, ISSN={1229-9197 1875-0052}, url={http://dx.doi.org/10.1007/BF02908163}, DOI={10.1007/bf02908163}, number={1}, journal={Fibers and Polymers}, publisher={Springer Science and Business Media LLC}, author={Seyam, Abdelfattah M. and Lee, Jin Ho and Hodge, George and Oxenham, William and Grant, Edward}, year={2007}, month={Jan}, pages={79–83} }
 @article{lee_seyam_hodge_oxenham_grant_2007, title={Warp breaks detection in Jacquard weaving using MEMS: System development}, volume={98}, ISSN={["0040-5000"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-35348829713&partnerID=MN8TOARS}, DOI={10.1080/00405000701462559}, abstractNote={Abstract Research related to warp breaks has been limited to monitoring break frequency and the reason associated with breaks in order to improve warp yarn quality. While this approach led to improvement in weaving efficiency, warp breaks still represent a major problem, especially for today's high-speed weaving machines. Researchers have been trying to develop commercial automated systems to repair warp breaks with no success. The goal of this study is to explore inexpensive methods to detect warp breaks using nontraditional technique that would pave the way to automate warp break repair. To achieve the goal, a system that can detect warp breaks using MEMS accelerometers as sensors was developed for Jacquard weaving. The MEMS accelerometers were mounted on harness cords of a Jacquard tie. MEMS output acceleration signals components in the vertical and horizontal directions were analysed using time and frequency domains. The signals were acquired while warp ends are running and at the moment of intentional breaks. The analysis led to a successful detection of warp breaks, especially using the horizontal acceleration component that is mainly due to harness cord vibration.}, number={3}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Lee, J. H. and Seyam, A. M. and Hodge, G. and Oxenham, W. and Grant, E.}, year={2007}, pages={275–280} }
 @article{palmer_jokiel_nordquist_kast_atwood_grant_livingston_medina_wicker_2006, title={Mesoscale RF relay enabled by integrated rapid manufacturing}, volume={12}, ISSN={["1758-7670"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33745063914&partnerID=MN8TOARS}, DOI={10.1108/13552540610670726}, abstractNote={Purpose This paper presents a novel mesoscale RF (mRF) relay that integrates advanced high resolution stereolithography (SL) and micro wire electro discharge machining ( μ EDM) technologies. Methods and infrastructure for reliable batch assembly of electromechanical actuators and structural parts less than 5 mm 3 in volume are described. Switches made using these techniques are expected to have greater power handling capability relative to current micro RF relay products. Design/methodology/approach The conjecture is that the integration of SL and similar rapid additive manufacturing with other mesofabrication technologies can yield innovative miniature products with novel capabilities. A series of mRF prototypes consisting of a contact mechanism and actuator with return spring were fabricated assembled, inspected, and characterized for electromechanical performance. Characterization results led to specific conclusions regarding capabilities of the mRF product, and the integrated manufacturing technique. Findings The microassembly apparatus and epoxy‐based fastening system led to durable prototypes within 4 h (excluding a 16‐24 h cure cycle). Relay stroke ranged from 560 to 1,650 μ m indicating a relative assembly accuracy of 90 percent. Prototypes demonstrated insertion loss of 1.3 dB at 100 MHz and isolation of better than 30 dB through 300 MHz. Research limitations/implications Results indicated that fully functional and robust mesoscale relays are possible using integrated manufacturing with SL. However, prototypes exhibited high contact resistance and lacked assembly precision in the context of contact mechanism stroke. Opportunities exist to reduce contact resistance and switching time. Practical implications The research provides a practical new product application for integrated mesoscale rapid manufacturing. Originality/value This work represents one of the first examples of a mesoscale relay rapidly manufactured with a combination of μ EDM and SL components.}, number={3}, journal={RAPID PROTOTYPING JOURNAL}, author={Palmer, J. A. and Jokiel, B. and Nordquist, C. D. and Kast, B. A. and Atwood, C. J. and Grant, E. and Livingston, F. J. and Medina, F. and Wicker, R. B.}, year={2006}, pages={148–155} }
 @article{nelson_grant_2006, title={Using direct competition to select for competent controllers in evolutionary robotics}, volume={54}, ISSN={["1872-793X"]}, DOI={10.1016/j.robot.2006.04.010}, abstractNote={Evolutionary robotics (ER) is a field of research that applies artificial evolution toward the automatic design and synthesis of intelligent robot controllers. The preceding decade saw numerous advances in evolutionary robotics hardware and software systems. However, the sophistication of resulting robot controllers has remained nearly static over this period of time. Here, we make the case that current methods of controller fitness evaluation are primary factors limiting the further development of ER. To address this, we define a form of fitness evaluation that relies on intra-population competition. In this research, complex neural networks were trained to control robots playing a competitive team game. To limit the amount of human bias or know-how injected into the evolving controllers, selection was based on whether controllers won or lost games. The robots relied on video sensing of their environment, and the neural networks required on the order of 150 inputs. This represents an order of magnitude increase in sensor complexity compared to other research in this field. Evolved controllers were tested extensively in real fully-autonomous robots and in simulation. Results and experiments are presented to characterize the training process and the acquisition of controller competency under different evolutionary conditions.}, number={10}, journal={ROBOTICS AND AUTONOMOUS SYSTEMS}, author={Nelson, Andrew L. and Grant, Edward}, year={2006}, month={Oct}, pages={840–857} }
 @article{grant_luthy_muth_mattos_braly_seyam_ghosh_dhawan_natarajan_2004, title={Developing Portable Acoustic Arrays on a Large-Scale E-Textile Substrate}, volume={16}, DOI={10.1108/09556220410520379}, abstractNote={This research deals with the production of electronic textiles (e‐textiles) demonstrators. Initially, the research dealt with the creation of 4×5 microphone array on a large area conformal textile substrate. Once the interface electronics were connected to the 4×5 microphone array, this system became an effective acoustic array. Here, a new acoustic eight microphone array design has been designed, fabricated and tested. Changes were made to improve microphone array performance, and to optimize the associated software for data capture and analysis. This new design was based on UC‐Berkeley mote microcomputer technology. The mote‐based system addresses the issue of scaling acoustic arrays, to allow for distributing microphones over large‐areas, and to allow performance comparisons to be made with the original 4×5 microphone acoustic array.}, number={1/2}, journal={International Journal of Clothing Science and Technology}, author={Grant, E. and Luthy, K. A. and Muth, J. F. and Mattos, L. S. and Braly, J. C. and Seyam, Abdel-Fattah and Ghosh, T. and Dhawan, A. and Natarajan, K.}, year={2004}, pages={73–83} }
 @article{nelson_grant_henderson_2004, title={Evolution of neural controllers for competitive game playing with teams of mobile robots}, volume={46}, ISSN={["1872-793X"]}, DOI={10.1016/j.robot.2004.01.001}, abstractNote={In this work, we describe the evolutionary training of artificial neural network controllers for competitive team game playing behaviors by teams of real mobile robots. This research emphasized the development of methods to automate the production of behavioral robot controllers. We seek methods that do not require a human designer to define specific intermediate behaviors for a complex robot task. The work made use of a real mobile robot colony (EVolutionary roBOTs) and a closely coupled computer-based simulated training environment. The acquisition of behavior in an evolutionary robotics system was demonstrated using a robotic version of the game Capture the Flag. In this game, played by two teams of competing robots, each team tries to defend its own goal while trying to ‘attack’ another goal defended by the other team. Robot neural controllers relied entirely on processed video data for sensing of their environment. Robot controllers were evolved in a simulated environment using evolutionary training algorithms. In the evolutionary process, each generation consisted of a competitive tournament of games played between the controllers in an evolving population. Robot controllers were selected based on whether they won or lost games in the course of a tournament. Following a tournament, the neural controllers were ranked competitively according to how many games they won and the population was propagated using a mutation and replacement strategy. After several hundred generations, the best performing controllers were transferred to teams of real mobile robots, where they exhibited behaviors similar to those seen in simulation including basic navigation, the ability to distinguish between different types of objects, and goal tending behaviors.}, number={3}, journal={ROBOTICS AND AUTONOMOUS SYSTEMS}, author={Nelson, AL and Grant, E and Henderson, TC}, year={2004}, month={Mar}, pages={135–150} }
 @article{nelson_grant_galeotti_rhody_2004, title={Maze exploration behaviors using an integrated evolutionary robotics environment}, volume={46}, ISSN={["1872-793X"]}, DOI={10.1016/j.robot.2003.11.002}, abstractNote={This paper presents results generated with a new evolutionary robotics (ER) simulation environment and its complementary real mobile robot colony research test-bed. Neural controllers producing mobile robot maze searching and exploration behaviors using binary tactile sensors as inputs were evolved in a simulated environment and subsequently transferred to and tested on real robots in a physical environment. There has been a considerable amount of proof-of-concept and demonstration research done in the field of ER control in recent years, most of which has focused on elementary behaviors such as object avoidance and homing. Artificial neural networks (ANN) are the most commonly used evolvable controller paradigm found in current ER literature. Much of the research reported to date has been restricted to the implementation of very simple behaviors using small ANN controllers. In order to move beyond the proof-of-concept stage our ER research was designed to train larger more complicated ANN controllers, and to implement those controllers on real robots quickly and efficiently. To achieve this a physical robot test-bed that includes a colony of eight real robots with advanced computing and communication abilities was designed and built. The real robot platform has been coupled to a simulation environment that facilitates the direct wireless transfer of evolved neural controllers from simulation to real robots (and vice versa). We believe that it is the simultaneous development of ER computing systems in both the simulated and the physical worlds that will produce advances in mobile robot colony research. Our simulation and training environment development focuses on the definition and training of our new class of ANNs, networks that include multiple hidden layers, and time-delayed and recurrent connections. Our physical mobile robot design focuses on maximizing computing and communications power while minimizing robot size, weight, and energy usage. The simulation and ANN-evolution environment was developed using MATLAB. To allow for efficient control software portability our physical evolutionary robots (EvBots) are equipped with a PC-104-based computer running a custom distribution of Linux and connected to the Internet via a wireless network connection. In addition to other high-level computing applications, the mobile robots run a condensed version of MATLAB, enabling ANN controllers evolved in simulation to be transferred directly onto physical robots without any alteration to the code. This is the first paper in a series to be published cataloging our results in this field.}, number={3}, journal={ROBOTICS AND AUTONOMOUS SYSTEMS}, author={Nelson, AL and Grant, E and Galeotti, JM and Rhody, S}, year={2004}, month={Mar}, pages={159–173} }
 @article{palmer_dessent_mulling_usher_grant_eischen_kingon_franzon_2004, title={The design and characterization of a novel piezoelectric transducer-based linear motor}, volume={9}, ISSN={["1941-014X"]}, DOI={10.1109/TMECH.2004.828647}, abstractNote={Before microminiature robots can be realized, new direct drive micromotor systems must be developed. In this research, a linear motor system for a miniature jumping robot was desired. However, current systems must display better force/torque characteristics than is currently available. This paper deals with the design, construction, and testing, of a macro-scale, unidirectional, direct drive linear piezomotor that operates like an inchworm. It uses a parallel arrangement of unimorph piezoelectric transducers, in conjunction with passive mechanical latches, to perform work on a coil spring. Experimental results showed that the linear piezomotor achieved a maximum no-load velocity of 161 mm/s, and a blocked force of 14 N, at a drive signal frequency of 100 Hz. Thereafter, back slip in the latch assembly restricted the forward motion. Based on the results obtained with the macro-level linear piezomotor, it is concluded that smaller direct drive piezomotor designs based on unimorph piezoelectric transducers are achievable. System scalability will be addressed in a future publication.}, number={2}, journal={IEEE-ASME TRANSACTIONS ON MECHATRONICS}, author={Palmer, JA and Dessent, B and Mulling, JF and Usher, T and Grant, E and Eischen, JW and Kingon, AI and Franzon, PD}, year={2004}, month={Jun}, pages={392–398} }
 @article{farer_seyam_ghosh_batra_grant_lee_2003, title={Forming shaped/molded structures by integrating meltblowing and robotic technologies}, volume={73}, ISSN={["0040-5175"]}, DOI={10.1177/004051750307300103}, abstractNote={A novel system is described that forms three-dimensional (3D) molded nonwoven structures through proper integration of a laboratory scale meltblown unit with a small die and a six-axis robot. The 3D fiberweb structures can be formed by deposition of fibers from the die of the meltblown unit, which is manipulated by the robot, on any desired 3D mold. The mold rotational and surface speeds can be controlled by an additional external axis. The die is connected by two flexible hoses to the melt extruder of the meltblown unit and a hot air supply system. This system directly sprays fibers onto a 3D mannequin mold to produce structures from polypropylene polymers. With varying degrees of success. several robot manipulation algorithms of fiber deposition on the mold are developed to accurately control the basis weight uniformity the fiberwebs. A rule-based control algorithm using a linear variable differential transducer to map the mold contour results in the greatest fiberweb basis weight uniformity.}, number={1}, journal={TEXTILE RESEARCH JOURNAL}, author={Farer, R and Seyam, AM and Ghosh, TK and Batra, SK and Grant, E and Lee, G}, year={2003}, month={Jan}, pages={15–21} }
 @article{farer_seyam_ghosh_grant_batra_2002, title={Meltblown structures formed by a robotic and meltblowing integrated system: Impact of process parameters on fiber orientation and diameter distribution}, volume={72}, ISSN={["0040-5175"]}, DOI={10.1177/004051750207201201}, abstractNote={In a previous publication, we described a novel system that forms three-dimensional (3D) structures on 3D molds and two-dimensional (2D) structures on a rotating drum through proper integration of a laboratory scale meltblown unit with a small die and a six-axis robot. In this paper, we investigate the impact of take-up speed. die-to-collector distance (DCD). polymer throughput rate. and attenuating air pressure on the fiber orien tation and diameter distribution of 2D structures formed by the system. We introduce a new parameter, the fiber stream approach angle, which can be precisely controlled by the robot, and discuss its impact on the meltblown structure. In the experimental range studied, fiber orientation and diameter distribution are significantly impacted by the parameters. Among these parameters. the fiber stream approach angle shows the highest effect on fiber orientation distribution.}, number={12}, journal={TEXTILE RESEARCH JOURNAL}, author={Farer, R and Seyam, AM and Ghosh, TK and Grant, E and Batra, SK}, year={2002}, month={Dec}, pages={1033–1040} }
 @misc{grant_muth_cottle_dessent_cox_2002, title={Modular observation crawler and sensing instrument and method for operating same}, volume={6,450,104}, number={2002 Sep. 17}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Grant, E. and Muth, J. F. and Cottle, J. S. and Dessent, B. E. and Cox, J. A.}, year={2002} }
 @article{mulling_usher_dessent_palmer_franzon_grant_kingon_2001, title={Load characterization of high displacement piezoelectric actuators with various end conditions}, volume={94}, ISSN={["0924-4247"]}, DOI={10.1016/S0924-4247(01)00688-4}, abstractNote={Piezoelectric ceramic transducers are characterized by relatively small strains on the order of 0.1%. One method of achieving significantly larger displacements is to utilize flexural mode actuators, such as unimorphs or bimorphs. In this paper, we investigate a particular type of stressed unimorph flexural actuator, viz. the ‘THUNDER’ actuators. (THUNDER™ is a trademark of Face International Corporation). These stressed unimorphs are of interest due to their particularly large flexural strains. To determine their versatility as high displacement actuators, it was necessary to investigate their actuation capability as a function of load. In addition, our investigation determined that end conditions have an appreciable effect, which has also not been reported in the literature. Therefore, experimental results of the load capabilities of these high displacement actuators with various end conditions are presented here. Commercially available rectangular actuators were chosen for this study. The actuators had been constructed by bonding thin PZT ceramics (0.152 mm thick, 1.37 cm wide, 3.81 cm long) to stainless steel sheets (0.20 mm thick, 1.27 cm wide, 6.35 cm long). They were operated in a flexural mode. It was shown that progressively restrictive end conditions increased the stiffness, ranging from 2.5 to 23 N/m, enhancing the load capabilities of the actuator. In some cases, displacement actually increased as a function of load. This enhanced stiffness was obtained at a cost of reduced no load flexural strain (defined as the ratio of flexural displacement and ceramic length), ranging from 1.08% for free-end conditions to 0.2% for highly restricted end conditions. The load bearing capabilities were tested out to 10 N for most end conditions.}, number={1-2}, journal={SENSORS AND ACTUATORS A-PHYSICAL}, author={Mulling, J and Usher, T and Dessent, B and Palmer, J and Franzon, P and Grant, E and Kingon, A}, year={2001}, month={Oct}, pages={19–24} }
 @article{grant_1997, title={Rapid prototyping}, volume={4}, number={3}, journal={IEEE Robotics & Automation Magazine}, author={Grant, E.}, year={1997}, pages={17–20} }