O. Araromi, C. J. Walsh, and R. J. Wood, “
Fabrication of Stretchable Composites with Anisotropic Electrical Conductivity for Compliant Pressure Transducers,” in
IEEE Sensors Conference 2016, Orlando, Florida, 2016.
Publisher's VersionAbstractWe present a simple fabrication approach for anisotropically conductive stretchable composites, towards novel flexible pressure transducers. Flexible electronic systems have gained great interest in recent years, and within this space, anisotropic conducting materials have been explored for enhanced sensing performance. However, current methods for producing these materials are complex or are limited to small fabrication areas. Our method uses film applicator coating to render commercially available conductive RTVs anisotropically conductive. A ratio of in-plane surface resistance to through-thickness resistance of 1010 was achieved using our method. Furthermore, we show that when a normal pressure is applied to such films, the in-plane resistance can be reduced by seven orders of magnitude for an applied pressure of 10 kPa. Hence these materials show great promise for the development of novel, robust pressure transducers.
PDF S. Lee, S. Crea, P. Malcolm, I. B. Galiana, A. T. Asbeck, and C. J. Walsh, “
Controlling Negative and Positive Power at the Ankle with a Soft Exosuit,” in
IEEE International Conference on Robotics and Automation (ICRA), Stockholm, Sweden, 2016, pp. 3509-3515.
Publisher's VersionAbstractThe soft exosuit is a new approach for applying assistive forces over the wearer's body through load paths configured by the textile architecture. In this paper, we present a body-worn lower-extremity soft exosuit and a new control approach that can independently control the level of assistance that is provided during negative- and positive-power periods at the ankle. The exosuit was designed to create load paths assisting ankle plantarflexion and hip flexion, and the actuation system transmits forces from the motors to the suit via Bowden cables. A load cell and two gyro sensors per leg are used to measure real-time data, and the controller performs position control of the cable on a step-by-step basis with respect to the power delivered to the wearer's ankle by controlling two force parameters, the pretension and the active force. Human subjects testing results demonstrate that the controller is capable of modulating the amount of power delivered to the ankle joint. Also, significant reductions in metabolic rate (11%-15%) were observed, which indicates the potential of the proposed control approach to provide benefit to the wearer during walking.
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