Abstract: A method to assemble a highly stretchable and highly sensitive strain sensor. Carbon nanofibers prepared by electrospinning of PAN followed by stabilization and carbonization, are sandwiched in two layers of elastomer PU. The CNFs/PU strain sensor shows large strain range of 300%, high sensitivity with gauge factor up to 72.5, and superior stability and durability during 8000 cycles of stretch/release. The CNFs/PU strain sensor shows fast, stable and reproducible responses following the bending movement of fingers, wrists, and elbows. The flexible CNFs/PU strain sensor with has broad applications in wearable devices for human motion monitoring.

Abstract: The present disclosure provides a simple method to assemble a highly stretchable and highly sensitive strain sensor. Carbon nanofibers prepared by electrospinning of PAN followed by stabilization and carbonization, are sandwiched in two layers of elastomer PU. The CNFs/PU strain sensor shows large strain range of 300%, high sensitivity with gauge factor up to 72.5, and superior stability and durability during 8000 cycles of stretch/release. These parameters meet the intended objectives of the present disclosure and distinguish the present disclosure from the piezoresistive strain sensors reported in the art. Additionally, the CNFs/PU strain sensor shows fast, stable and reproducible responses following the bending movement of fingers, wrists, and elbows. A flexible CNFs/PU strain sensor with the properties disclosed herein can have broad applications in wearable devices for human motion monitoring.

Abstract: A regenerative variable frequency drive includes an active converter connected to an inverter. The converter has a filter capacitor, an inductor, two half bridges, bus bars that connect to the inverter and bus capacitors. The converter converts single phase AC power to DC power and DC power to single phase AC power, boosts the AC power, reduces input line harmonics, maintains input current in phase with utility voltage in order to achieve near unity power factor, and maintains constant DC voltage between the bus bars.