Self‐Shaping Soft Electronics Based on Patterned Hydrogel with Stencil‐Printed Liquid Metal

• Published in: Advanced functional materials Vol. 31; no. 47
• Main Authors: Hao, Xing Peng, Li, Chen Yu, Zhang, Chuan Wei, Du, Miao, Ying, Zhimin, Zheng, Qiang, Wu, Zi Liang
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.11.2021
• Subjects: Elastomers; Electronics; Hydrogels; Liquid metals; Low conductivity; Materials science; Mechanical properties; Morphing; morphing structures; Object recognition; Organs; Polymer films; soft electronics; stencil patterning; Substrates; Tissues; tough hydrogels
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202105481

Hydrogel‐based soft electronics (HSE) is promising as implantable devices due to the similarity of hydrogel substrates to biologic tissues. Most existing HSE devices are based on conducting hydrogels that usually have weak mechanical properties, low conductivity, and poor patternability. Reported here is an HSE with good mechanical performance, high sensitivity, and versatile functions by stencil printing of liquid metal on a tough hydrogel, facilitating integration of multiple sensing units. Self‐shaping ability is imparted to the HSE by creating gradient structure in the hydrogel substrate. The resultant HSE actively deforms into 3D configurations with zero or nonzero Gaussian curvature to fix on objects or organs with sophisticated geometries and maintains the sensing functions. The versatilities and potential applications of this HSE are demonstrated by monitoring motions of a rice field eel and beatings of a rabbit heart. Such HSE based on morphing substrate should pave the way for implantable electronics with better fixation and interfacial contact with the organs. The concept of morphing hydrogel devices can be extended to other soft electronics with responsive polymer films or elastomers as the substrates. Hydrogel‐based soft electronics with self‐shaping ability is realized by creating gradients in hydrogel substrates embedded with stencil printed liquid metal. The devised hydrogel electronics can morph into 3D configurations to fix on objects or organs with sophisticated geometries to implement motion detecting and healthcare monitoring.