A Highly Stretchable, Sensitive Strain Sensor Based on the Dry Printing Method

Abstract

Use of Electronic skin (E-skin) has attracted significant attention, as it has broad application prospects in medical care, wearable electronic equipment, and body monitoring — particularly with respect to human motion detection. In this work, we developed a flexible, tensile strain sensor based on the dry printing method. A conductive layer, with a miniaturized network structure, was obtained by: (1) packing the grooves of a grid-like silicon template with a conductive powder composed of carbon nanotubes (CNTs) and silicon dioxide (SiO[Formula: see text] nanoparticles; (2) infiltrating liquid polydimethylsiloxane (PDMS) into the powder voids using a coated, flexible PDMS substrate cover; (3) transferring the solidified, patterned conductive powder onto the flexible substrate by peeling the PDMS substrate cover off the template; (4) fabricating metal electrodes at both ends of the conductive layer and (5) encapsulating the strain sensor with liquid PDMS. After manufacture, the strain sensor was tested using the tensile test. Results from the tensile test demonstrate that the sensor has excellent electrical conductivity, including super high-sensitivity [Formula: see text], a large strain range (up to 35%), and good transparency; as ultraviolet (UV) spectrum analysis shows that the transmittance can reach [Formula: see text]%. Thus, the sensor is potentially applicable to numerous sub-specialties that require specialized electronics.