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

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 498; p. 154934
• Main Authors: Cai, Xinxin, Wang, Xinqi, Bian, Fuping, Li, Jiayi, Zhou, Ruixiang, Hu, Jiwen, Lin, Shudong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2024
• Subjects: AgNWs; Elastomers; Electronic skin; Flexible sensor; Human motion detection; Flexible sensor; Electronic skin; Human motion detection; AgNWs; Elastomers
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.154934

[Display omitted] •The sandwich-structured flexible sensor was prepared from AgNWs and P32-PDMS elastomer.•P32-PDMS elastomer is synthesized by blending and modifying PDMS with PEG-PPG-PEG.•Compared with PDMS, P32-PDMS elastomer has low Young’s modulus, high elongation at break, good adhesion, certain light transmittance and biocompatibility.•The flexible sensor possesses the characteristics of high sensitivity, wide detection range, excellent cycle stability, and good durability.•The flexible sensors act as e-skin that respond well to slight and high strain body movements. 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.