Bioinspired Flexible Hydrogelation with Programmable Properties for Tactile Sensing

Adv Mater. 2024 Apr 28:e2401678. doi: 10.1002/adma.202401678. Online ahead of print.

Abstract

Tactile sensing requires integrated detection platforms with distributed and highly-sensitive haptic sensing capabilities along with biocompatibility, aiming to replicate the physiological functions of the human skin and empower industrial robotic and prosthetic wearers to detect tactile information. In this regard, short peptide-based self-assembled hydrogels show promising potential to act as bioinspired supramolecular substrates for developing tactile sensors showing biocompatibility and biodegradability. However, the intrinsic difficulty to modulate the mechanical properties severely restricts their extensive employment. Herein, by controlling the self-assembly of 9-fluorenylmethoxycarbonyl-modifid diphenylalanine (Fmoc-FF) through introduction of polyethylene glycol diacrylate (PEGDA), wider nanoribbons are achieved by untwisting from well-established thinner nanofibers, and the mechanical properties of the supramolecular hydrogels can be enhanced 10-fold, supplying bioinspired supramolecular encapsulating substrate for tactile sensing. Furthermore, by doping with PEDOT:PSS and 9-fluorenylmethoxycarbonyl-modifid 3,4-dihydroxy-L-phenylalanine (Fmoc-DOPA), the Fmoc-FF self-assembled hydrogels can be engineered to be conductive and adhesive, providing bioinspired sensing units and adhesive layer for tactile sensing applications. Therefore, the integration of these modules results in peptide hydrogelation-based tactile sensors, showing high sensitivity and sustainable responses with intrinsic biocompatibility and biodegradability. Our findings establish the feasibility of developing programmable peptide self-assembly with adjustable features for tactile sensing applications. This article is protected by copyright. All rights reserved.

Keywords: aromatic short peptides; bioinspired electronics; hydrogelation; molecular manufacturing; tactile sensing.