@article{turner_twiddy_wilkins_ramesh_kilgour_domingos_nasrallah_menegatti_daniele_2023, title={Biodegradable elastomeric circuit boards from citric acid-based polyesters}, volume={7}, ISSN={["2397-4621"]}, DOI={10.1038/s41528-023-00258-z}, abstractNote={Abstract Recyclable and biodegradable microelectronics, i.e., “green” electronics, are emerging as a viable solution to the global challenge of electronic waste. Specifically, flexible circuit boards represent a prime target for materials development and increasing the utility of green electronics in biomedical applications. Circuit board substrates and packaging are good dielectrics, mechanically and thermally robust, and are compatible with microfabrication processes. Poly(octamethylene maleate (anhydride) citrate) (POMaC) – a citric acid-based elastomer with tunable degradation and mechanical properties – presents a promising alternative for circuit board substrates and packaging. Here, we report the characterization of Elastomeric Circuit Boards (ECBs). Synthesis and processing conditions were optimized to achieve desired degradation and mechanical properties for production of stretchable circuits. ECB traces were characterized and exhibited sheet resistance of 0.599 Ω cm −2 , crosstalk distance of <0.6 mm, and exhibited stable 0% strain resistances after 1000 strain cycles to 20%. Fabrication of single layer and encapsulated ECBs was demonstrated.}, number={1}, journal={NPJ FLEXIBLE ELECTRONICS}, author={Turner, Brendan L. and Twiddy, Jack and Wilkins, Michael D. and Ramesh, Srivatsan and Kilgour, Katie M. and Domingos, Eleo and Nasrallah, Olivia and Menegatti, Stefano and Daniele, Michael A.}, year={2023}, month={Jun} }
 @article{twiddy_peterson_maddocks_macpherson_pimentel_yates_armitano-lago_kiefer_pietrosimone_franz_et al._2022, title={A Low-Cost, Open Source Wireless Body Area Network for Clinical Gait Rehabilitation}, ISSN={["1930-0395"]}, DOI={10.1109/SENSORS52175.2022.9967362}, abstractNote={Wearable inertial sensors represent an opportunity to enable gait monitoring and feedback-based rehabilitation in real-world environments. Here, we describe the development of an inexpensive I MU-based wireless body area network capable of recording 9-axis motion data from 8 sites on the body simultaneously. This system can generate data comparable to existing commercial sensor networks and can distinguish varying loading conditions observed during real-time biofeedback-based human subject testing.}, journal={2022 IEEE SENSORS}, author={Twiddy, Jack and Peterson, Kaila and Maddocks, Grace and MacPherson, Ryan and Pimentel, Ricky and Yates, Max and Armitano-Lago, Cortney and Kiefer, Adam and Pietrosimone, Brian and Franz, Jason and et al.}, year={2022} }
 @article{suh_twiddy_mahmood_ali_lubna_bradford_daniele_gluck_2022, title={Electrospun Carbon Nanotube-Based Scaffolds Exhibit High Conductivity and Cytocompatibility for Tissue Engineering Applications}, volume={7}, ISSN={["2470-1343"]}, url={https://doi.org/10.1021/acsomega.2c01807}, DOI={10.1021/acsomega.2c01807}, abstractNote={Carbon nanotubes (CNTs) are known for their excellent conductive properties. Here, we present two novel methods, “sandwich” (sCNT) and dual deposition (DD CNT), for incorporating CNTs into electrospun polycaprolactone (PCL) and gelatin scaffolds to increase their conductance. Based on CNT percentage, the DD CNT scaffolds contain significantly higher quantities of CNTs than the sCNT scaffolds. The inclusion of CNTs increased the electrical conductance of scaffolds from 0.0 ± 0.00 kS (non-CNT) to 0.54 ± 0.10 kS (sCNT) and 5.22 ± 0.49 kS (DD CNT) when measured parallel to CNT arrays and to 0.25 ± 0.003 kS (sCNT) and 2.85 ± 1.12 (DD CNT) when measured orthogonally to CNT arrays. The inclusion of CNTs increased fiber diameter and pore size, promoting cellular migration into the scaffolds. CNT inclusion also decreased the degradation rate and increased hydrophobicity of scaffolds. Additionally, CNT inclusion increased Young’s modulus and failure load of scaffolds, increasing their mechanical robustness. Murine fibroblasts were maintained on the scaffolds for 30 days, demonstrating high cytocompatibility. The increased conductivity and high cytocompatibility of the CNT-incorporated scaffolds make them appropriate candidates for future use in cardiac and neural tissue engineering.}, number={23}, journal={ACS OMEGA}, publisher={American Chemical Society (ACS)}, author={Suh, Taylor C. and Twiddy, Jack and Mahmood, Nasif and Ali, Kiran M. and Lubna, Mostakima M. and Bradford, Philip D. and Daniele, Michael A. and Gluck, Jessica M.}, year={2022}, month={Jun}, pages={20006–20019} }
 @article{twiddy_taggart_reynolds_sharkey_rufty_lobaton_bozkurt_daniele_2022, title={Real-Time Monitoring of Plant Stalk Growth Using a Flexible Printed Circuit Board Sensor}, ISSN={["1930-0395"]}, DOI={10.1109/SENSORS52175.2022.9967167}, abstractNote={Monitoring of plant growth within agriculture is essential for ensuring the survival of crops and optimization of resources in the face of environmental and industrial challenges. Herein, we describe a low-cost and easily deployable flexible circuit board sensor for measurement of plant stalk growth, providing for remote tracking of plant development on an industrial scale. Three circuit topologies and measurement strategies - “ladder-type,” “multiplex-type,” and “mixed-type” - are initially assessed off-plant in a simulated growth experiment. Further development of the “multiplex-type” sensor and on-plant validation demonstrates its ability to quantify stalk growth as a proxy for plant development.}, journal={2022 IEEE SENSORS}, author={Twiddy, Jack and Taggart, Matthew and Reynolds, James and Sharkey, Chris and Rufty, Thomas and Lobaton, Edgar and Bozkurt, Alper and Daniele, Michael}, year={2022} }
 @article{iezzi_ankireddy_twiddy_losego_jur_2017, title={Printed, metallic thermoelectric generators integrated with pipe insulation for powering wireless sensors}, volume={208}, ISSN={["1872-9118"]}, DOI={10.1016/j.apenergy.2017.09.073}, abstractNote={Abstract The Internet of Things (IoT), coupled with advanced analytics, is poised to revolutionize manufacturing maintenance and efficiency. However, a practical route to powering these many IoT devices remains unclear. In this work, flexible thermoelectric generators (TEGs) are fabricated from low cost, screen printed silver and nickel inks before being integrated into a novel form factor device based on commercial steam pipe insulation. Through optimization of internal resistances and total device design, this 420-junction TEG device produces 308 µW of power at a temperature difference of 127 K. This is sufficient to power a temperature sensing circuit with wireless communication capabilities. In this report we demonstrate that, after an initial 4 h of charging, this TEG can power a standard RFduino microcontroller for 10 min while sending temperature readings every 30 s via Bluetooth Low Energy (BLE) to a cell phone. Additional optimization and scaling could further increase system efficiency and provide a viable route to powering an industrial wireless sensing network (WSN).}, journal={APPLIED ENERGY}, author={Iezzi, Brian and Ankireddy, Krishnamraju and Twiddy, Jack and Losego, Mark D. and Jur, Jesse S.}, year={2017}, month={Dec}, pages={758–765} }