@inproceedings{agcayazi_mcknight_kausche_ghosh_bozkurt_2016, title={A finger touch force detection method for textile based capacitive tactile sensor arrays}, DOI={10.1109/icsens.2016.7808528}, abstractNote={The use of touch-based technology to interact with electronic devices pre-dates modern day multi-touch technology and even the personal computer. It has recently been growing in popularity in wearable computing devices especially in the form of textile based tactile sensor. These sensors often target the detection of not only touch but also force applied. A significant problem arises here in differentiating inputs from an intended finger touch and just a bend of the sensor or other objects touching the sensor. In this work, we present our initial efforts to differentiate between a finger and an insulated object touch event on a custom textile based tactile sensor we developed before. Our experiments show that the two cases could be differentiated using the capacitance change of the neighboring cross-over points.}, booktitle={2016 ieee sensors}, author={Agcayazi, T. and McKnight, M. and Kausche, H. and ghosh and Bozkurt, A.}, year={2016} } @article{dieffenderfer_goodell_mills_mcknight_yao_lin_beppler_bent_lee_misra_et al._2016, title={Low-Power Wearable Systems for Continuous Monitoring of Environment and Health for Chronic Respiratory Disease}, volume={20}, ISSN={2168-2194 2168-2208}, url={http://dx.doi.org/10.1109/JBHI.2016.2573286}, DOI={10.1109/jbhi.2016.2573286}, abstractNote={We present our efforts toward enabling a wearable sensor system that allows for the correlation of individual environmental exposures with physiologic and subsequent adverse health responses. This system will permit a better understanding of the impact of increased ozone levels and other pollutants on chronic asthma conditions. We discuss the inefficiency of existing commercial off-the-shelf components to achieve continuous monitoring and our system-level and nano-enabled efforts toward improving the wearability and power consumption. Our system consists of a wristband, a chest patch, and a handheld spirometer. We describe our preliminary efforts to achieve a submilliwatt system ultimately powered by the energy harvested from thermal radiation and motion of the body with the primary contributions being an ultralow-power ozone sensor, an volatile organic compounds sensor, spirometer, and the integration of these and other sensors in a multimodal sensing platform. The measured environmental parameters include ambient ozone concentration, temperature, and relative humidity. Our array of sensors also assesses heart rate via photoplethysmography and electrocardiography, respiratory rate via photoplethysmography, skin impedance, three-axis acceleration, wheezing via a microphone, and expiratory airflow. The sensors on the wristband, chest patch, and spirometer consume 0.83, 0.96, and 0.01 mW, respectively. The data from each sensor are continually streamed to a peripheral data aggregation device and are subsequently transferred to a dedicated server for cloud storage. Future work includes reducing the power consumption of the system-on-chip including radio to reduce the entirety of each described system in the submilliwatt range.}, number={5}, journal={IEEE Journal of Biomedical and Health Informatics}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Dieffenderfer, James and Goodell, Henry and Mills, Steven and McKnight, Michael and Yao, Shanshan and Lin, Feiyan and Beppler, Eric and Bent, Brinnae and Lee, Bongmook and Misra, Veena and et al.}, year={2016}, month={Sep}, pages={1251–1264} } @inproceedings{mcknight_agcayazi_kausche_ghosh_bozkurt_2016, title={Sensing textile seam-line for wearable multimodal physiological monitoring}, DOI={10.1109/embc.2016.7590702}, abstractNote={This paper investigates a novel multimodal sensing method by forming seam-lines of conductive textile fibers into commercially available fabrics. The proposed ultra-low cost micro-electro-mechanical sensor would provide, wearable, flexible, textile based biopotential signal recording, wetness detection and tactile sensing simultaneously. Three types of fibers are evaluated for their array-based sensing capability, including a 3D printed conductive fiber, a multiwall carbon nanotube based fiber, and a commercially available stainless steel conductive thread. The sensors were shown to have a correlation between capacitance and pressure; impedance and wetness; and recorded potential and ECG waveforms.}, booktitle={2016 38th annual international conference of the ieee engineering in medicine and biology society (embc)}, author={McKnight, M. and Agcayazi, T. and Kausche, H. and ghosh and Bozkurt, A.}, year={2016}, pages={311–314} } @inproceedings{lin_yao_mcknight_zhu_bozkurt_2016, title={Silver nanowire based wearable sensors for multimodal sensing}, DOI={10.1109/biowireless.2016.7445561}, abstractNote={We present multifunctional sensors based on highly stretchable silver nanowire conductors, which can be conformally attached to human skin for multimodal sensing. The wearable sensors were integrated with an interface circuit with wireless capability in the form of a chest patch. The capabilities of electrocardiography, strain/motion sensing and skin impedance sensing were demonstrated. Additionally, the impedance sensor with the interface circuit was packaged into a wrist watch for skin impedance monitoring.}, booktitle={Ieee topical conference on biomedical wireless technologies networks and}, author={Lin, F. Y. and Yao, S. S. and McKnight, M. and Zhu, Y. and Bozkurt, A.}, year={2016}, pages={55–58} } @inproceedings{kapoor_mcknight_chatterjee_agcayazi_kausche_ghosh_bozkurt_2016, place={Orlando, FL, USA}, title={Soft, flexible 3D printed fibers for capacitive tactile sensing}, url={http://ieeexplore.ieee.org/document/7808918/}, DOI={10.1109/icsens.2016.7808918}, abstractNote={This study presents our latest efforts towards developing a force sensor array by weaving 3D printed functionalized polymer fibers. Silicone was used as the base polymer and carbon fillers were used to impart electrical conductivity. Two “H”-shaped fiber cross-sections oriented orthogonally acted as a parallel plate capacitor and were used for detecting normal forces. In this article, we present the fabrication method of the unique “H”-shaped fiber cross-section along with the investigation of the relation between applied force and measured capacitance. We also report the sensor response to variation in temperature. The sensing crossover was found to have a stable mechanical and electrical response in the force range of 0–6 N and the performance of this soft sensor was not significantly affected by temperature.}, booktitle={2016 ieee sensors}, author={Kapoor, A. and McKnight, M. and Chatterjee, K. and Agcayazi, T. and Kausche, H. and ghosh and Bozkurt, A.}, year={2016}, pages={1–3} } @inproceedings{howell_nag_mcknight_narsipur_adelegan_2015, title={A low-power wearable substance monitoring device}, DOI={10.1109/vcacs.2015.7439567}, abstractNote={Alcohol and illicit drug abuse has become a major problem in recent years. According to US Census, there are approximately 40 million teenagers between the age of 10-19, and 20% of them have used an illegal substance at least once in their lifetime. Therefore, by extrapolation, there are potentially 8 million drug abuse cases across the board. This opens up a major requirement for drug monitoring and devices capable of monitoring drug abusers or helping addicts recover. Previous research has shown that certain quantifiable physiological parameters become altered following illicit drug or alcohol consumption. A solution that addresses the problem of detecting drug abuse is the core focus of this research. Initial steps have been focused on developing a device in the form of a wrist-watch that is capable of measuring selected physiological parameters using commercially available sensors. An Android application with algorithms capable of determining if the user is under the influence of alcohol or drugs has been developed and tested.}, booktitle={2015 Virtual Conference on Application of Commercial Sensors}, author={Howell, J. and Nag, A. and McKnight, M. and Narsipur, S. and Adelegan, O.}, year={2015} } @article{verderber_mcknight_bozkurt_2014, title={Early Metamorphic Insertion Technology for Insect Flight Behavior Monitoring}, ISSN={["1940-087X"]}, DOI={10.3791/50901}, abstractNote={Early Metamorphosis Insertion Technology (EMIT) is a novel methodology for integrating microfabricated neuromuscular recording and actuation platforms on insects during their metamorphic development. Here, the implants are fused within the structure and function of the neuromuscular system as a result of metamorphic tissue remaking. The implants emerge with the insect where the development of tissue around the electronics during pupal development results in a bioelectrically and biomechanically enhanced tissue interface. This relatively more reliable and stable interface would be beneficial for many researchers exploring the neural basis of the insect locomotion with alleviated traumatic effects caused during adult stage insertions. In this article, we implant our electrodes into the indirect flight muscles of Manduca sexta. Located in the dorsal-thorax, these main flight powering dorsoventral and dorsolongitudinal muscles actuate the wings and supply the mechanical power for up and down strokes. Relative contraction of these two muscle groups has been under investigation to explore how the yaw maneuver is neurophysiologically coordinated. To characterize the flight dynamics, insects are often tethered with wires and their flight is recorded with digital cameras. We also developed a novel way to tether Manduca sexta on a magnetically levitating frame where the insect is connected to a commercially available wireless neural amplifier. This set up can be used to limit the degree of freedom to yawing "only" while transmitting the related electromyography signals from dorsoventral and dorsolongitudinal muscle groups.}, number={89}, journal={JOVE-JOURNAL OF VISUALIZED EXPERIMENTS}, author={Verderber, Alexander and McKnight, Michael and Bozkurt, Alper}, year={2014}, month={Jul} }