Abstract
Transparent stretchable (TS) sensors capable of detecting and distinguishing touch and pressure inputs are a promising development in wearable electronics. However, realization of such a device has been limited by difficulties in achieving optical transparency, stretchability, high sensitivity, stability, and distinguishable responsivity to two stimuli simultaneously. Herein, we report a TS sensor in which touch and pressure stimuli can be detected and distinguished on a substrate with a stress-relieving three-dimensional (3D) microstructured pattern providing multidirectional stretchability and increased pressure sensitivity. The TS capacitive device structure is a dielectric layer sandwiched between an upper piezoresistive electrode of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/ionic liquid composite, which enables touch and pressure stimuli to be distinguished, and a lower electrode of metal/indium tin oxide/metal multilayer. The TS sensor array was demonstrated as a wearable input device for controlling a small vehicle. The TS touch-pressure sensor has great potential to be used as a multimodal input device for future wearable electronics.
Highlights
A 3D micropatterned PDMS was replicated from the mold, and a PU acrylate (PUA) master mold was replicated from the PDMS mold for repeated replication of the PDMS substrate
The sensor was fabricated by sequentially forming an ultrathin metal GIG lower electrode layer, a dielectric layer using a watersoluble dispersion of PU, a piezoresistive upper electrode layer using a poly(styrenesulfonate)/1-ethyl-3methylimidazolium tetracyanoborate (PEDOT):PSS/EMIM-TCB composite, and an encapsulation layer of PDMS on a 3D micropatterned PDMS substrate[34]
Increased deformation of the piezoresistive upper electrode on the bumps under vertical pressure leads to an increase in the sensitivity to pressure when the surface charges induced in the capacitor structure are read as an alternating current (AC) signal
Summary
Over the past few years, numerous studies have been conducted to develop stretchable physical sensors for human–machine interfaces that can be worn or conformally attached to human skin[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24]. Reports of a single stretchable multimodal device and its array as a conformally wearable input device are rare
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
