Wearable, Healable, and Adhesive Epidermal Sensors Assembled from Mussel‐Inspired Conductive Hybrid Hydrogel Framework

Abstract

Healable, adhesive, wearable, and soft human-motion sensors for ultrasensitive human-machine interaction and healthcare monitoring are successfully assembled from conductive and human-friendly hybrid hydrogels with reliable self-healing capability and robust self-adhesiveness. The conductive, healable, and self-adhesive hybrid network hydrogels are prepared from the delicate conformal coating of conductive functionalized single-wall carbon nanotube (FSWCNT) networks by dynamic supramolecular cross-linking among FSWCNT, biocompatible polyvinyl alcohol, and polydopamine. They exhibit fast self-healing ability (within 2 s), high self-healing efficiency (99%), and robust adhesiveness, and can be assembled as healable, adhesive, and soft human-motion sensors with tunable conducting channels of pores for ions and framework for electrons for real time and accurate detection of both large-scale and tiny human activities (including bending and relaxing of fingers, walking, chewing, and pulse). Furthermore, the soft humanmotion sensors can be enabled to wirelessly monitor the human activities by coupling to a wireless transmitter. Additionally, the in vitro cytotoxicity results suggest that the hydrogels show no cytotoxicity and can facilitate cell attachment and proliferation. Thus, the healable, adhesive, wearable, and soft human-motion sensors have promising potential in various wearable, wireless, and soft electronics for human-machine interfaces, human activity monitoring, personal healthcare diagnosis, and therapy.

Double‐Hydrophobic‐Coating through Quenching for Hydrogels with Strong Resistance to Both Drying and Swelling

“…This kind of physical adsorption‐based adhesion may also be applicable for various dry surfaces (e.g., metals, ceramics, and plastics) and wet surfaces (e.g., hydrogels and biotissues); however, future extensive studies should be carried out to further clarify this. The adhesive property of our system is comparable to commonly used mussel‐inspired catechol‐based hydrogels and other recently developed adhesive hydrogels that rely on supramolecular interactions for adhesion (Table S1, Supporting Information) . Notably, while most adhesive hydrogels (apart from nanoparticle adhesives) require internal modification of the chemical structure—which ultimately changes the properties compared to the original unmodified hydrogel—our strategy only alters the surface structure.…”

Softening and Shape Morphing of Stiff Tough Hydrogels by Localized Unlocking of the Trivalent Ionically Cross‐Linked Centers

“…Third, unfolding and refolding of the structures can be realized by sequentially printing the VC solution in a stepwise manner. More importantly, the current study introduces a chemical‐triggering strategy, which can be exploited for actuators or sensors . We thus envision that the actuation of the tough hydrogel‐integrated thin film devices can be triggered when exposed to a reducing agent.…”

Conductive Hydrogels as Smart Materials for Flexible Electronic Devices

“…Copyright 2017, Wiley‐VCH. (c) Soft human‐motion sensors assembled from the hybrid network hydrogels could be reversibly self‐healed, and self‐adhered on the wrist during the human‐machine interaction and healthcare monitoring . Copyright 2017, Wiley‐VCH.…”

“…Self‐healing capability could repair the sensors to their original states when they suffered damaged, endowing these sensors with enhanced durability and extended lifetime. Based on this, a self‐healable, wearable human‐motion soft sensors was fabricated for healthcare monitoring . The sensor derived from a conductive hybrid network hydrogel prepared by dynamic cross‐linking among conductive functionalized single‐wall carbon nanotube, PVA and PDA.…”

“…Conductive hydrogels are an ideal candidate for use in flexible electronic devices due to their unique properties such as good electronic properties, tunable mechanical flexibility, and easy to process. In addition, hydrogel materials have remarkable biological characteristics (such as self‐healing, self‐adhesive, anti‐microbial activity and biocompatibility) to fulfill special demands . Therefore, in recent years, conductive hydrogels have been an active field of research flexible electronics present promising possibilities for flexible electrodes, flexible mechanical sensors, flexible displays and other devices with the human body .…”