Flexible sensor based on conformable, sticky, transparent elastomers for electronic skin

Abstract

As 5G technology advances and enhances the interconnection of science and technology, the demand for advanced sensors has increased. Conventional rigid sensors are inadequate to meet these new requirements, thus sparking significant interest in flexible sensors. However, taking into account the biocompatibility, skin compliance, sensing performance, mechanical properties and optical properties of flexible sensors is still the direction of efforts. Therefore, in this study, the flexible sensor with a sandwich structure was prepared using AgNWs as a conductive filler and P32-PDMS elastomer as a flexible substrate. The PDMS elastomer is modified by blending PEG-PPG-PEG and PDMS, giving the P32-PDMS elastomer low Young’s modulus (32.35 kPa), high elongation at break (over 450 %) and good adhesion (18.94 N/m), and the P32-PDMS elastomer still retains a certain light transmittance (82.22 %) and biocompatibility (RGR=89.524). These properties simultaneously endow the flexible sensor with good sensitivity (GF=17.27), wide detection range (0–100 % strain), and excellent cycling stability (5000 cycles). When the flexible sensor is used as e-skin to monitor human body movements, stable signals are generated regardless of the low-strain movements of the human body (pulse and sound) or the high-strain movements of the human body (pressing and joint bending). Therefore, the prepared flexible sensor has great potential as e-skin in many fields such as personal health monitoring, human motion detection, human–computer interaction, flexible display, etc.