Flexible sensors

Finger motion capturing systems have a wide variety of applications such as telerobotics, rehabilitation, and avatar control. While commercial devices are too costly, studies on such systems are either impractical to use or have speed limitations. This paper proposes a practical version of the glovebased finger motion capturing system.

In this work, we developed a conductive silver nanowire (AgNW)-PDMS composite thin film for a flexible strain sensing application. The piezoresistivity of AgNWs-PDMS nanocomposite thin film was experimentally investigated and analyzed by a computational model. The strain sensor shows a strong piezoresistivity with an average gauge factor in the ranges of 1.6 to 14 and a high stretchability up to 70 %. We found excellent agreement between our experiment and simulation results.

We developed highly stretchable, flexible and very soft conductors based on the carbon nanotubes (CNTs)-silicone rubber (Ecoflex®) nanocomposite thin films. The resistance of the CNTs-Ecoflex nanocomposite thin film was recovered to its original value under cyclic loading/unloading for strains as large as 510%. Failure strain of the CNTs-Ecoflex nanocomposite was measured to be about ~ 1380% showing its ultra-high stretchability and robustness. As an application of our highly stretchable conductors, we utilized them as skin-mountable and wearable strain sensors for human motion detection.

In this work, we develop high flexible and compressible porous PDMS structures by using sugar cubes as templates. Force sensitive resistor (FSR) sensors were fabricated by the filtration of the CNT solution inside the porous structure of PDMS. We found that sufficient acid treatment can increase the adhesion between CNTs and PDMS. FSR sensors respond the applied pressure and compressive strains by high linearity (R2>0.97) and sensitivity (GFs>2) with a reliable manner.