Stretchable and Sensitive Silver Nanowire-Hydrogel Strain Sensors for Proprioceptive Actuation

• Published in: ACS applied materials & interfaces 2021-08, Vol.13 (31), p.37816-37829
• Main Authors: Kumar, Kirthika Senthil, Zhang, Lei, Kalairaj, Manivannan Sivaperuman, Banerjee, Hritwick, Xiao, Xiao, Jiayi, Catherine Cai, Huang, Hui, Lim, Chwee Ming, Ouyang, Jianyong, Ren, Hongliang
• Format: Article
• Language: English
• Subjects: Surfaces, Interfaces, and Applications
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c08305

Safer human–robot interactions mandate the adoption of proprioceptive actuation. Strain sensors can detect the deformation of tools and devices in unstructured and capricious environments. However, such sensor integration in surgical/clinical settings is challenging due to confined spaces, structural complexity, and performance losses of tools and devices. Herein, we report a highly stretchable skin-like strain sensor based on a silver nanowire (AgNW) layer and hydrogel substrate. Our facile fabrication method utilizes thermal annealing to modulate the gauge factor (GF) by forming multidimensional wrinkles and a layered conductive network. The developed AgNW-hydrogel (AGel) sensors sustain and exhibit a strain-sensitive profile (max. GF = ∼70) with high stretchability (200%). Due to its conformability, the sensor demonstrates efficacy in integration and motion monitoring with minimal mechanical constraints. We provide contextual cognizance of tooltip during a transoral procedure by incorporating AGel sensors and showing the fabrication methodology’s versatility by developing a hybrid self-sensing actuator with real-time performance feedback.