Electronic materials and devices that can mimic biological systems with features including elasticity, toughness, self-healing, degradability and environmentally benign drive the technological developments in fields spanning from bioelectronics, biomedical diagnosis and therapy, electronic skin, soft robotics to Internet-of-Things with “green” electronics. Among them, ionic devices based on gel electrolytes have arisen as attracting candidates for biomimetic systems. A key challenge in gel-based devices remains in the robust electrode/electrolyte interface. Inspired by the skin structure that involves microstructured interface, we demonstrated that a surface-microstructured tough hydrogel electrolyte composed of agar/polyacrylamide/LiCl (AG/PAAm/LiCl) could be exploited to allow stretchable supercapacitors with enhanced mechanical and electrochemical performance. Alternatively, a tannic-acid-soaking method was employed to enable resilient, adhesive and redox-active tough gel electrolytes. Furthermore, a straightforward approach is developed to demonstrate soft ionic microdevices based on a versatile organohydrogel platform acting as both a free-standing, stretchable, adhesive, healable and entirely degradable support and a highly conductive, dehydration- and freezing-tolerant electrolyte. This is achieved by forming a gelatin / ferric-ion-crosslinked polyacrylic acid (GEL/PAA) dual dynamic supramolecular network, followed by soaking into a NaCl glycerol/water solution to further toughen the gelatin via solvent displacement. The present approach for the organohydrogel-based ionic microdevices will provide promising scope for life-like and sustainable electronic systems.

Stretchable ionic microdevices based on multifunctional hydrogel electrolytes

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.