Wearable and Flexible Hydrogels for Strain Sensing and Wound Electrical Stimulation

Abstract

Conductive hydrogels have attracted a great deal of interest in health testing and electrical stimulation therapy. To improve the inherent brittleness and stickiness of hydrogels, a multifunctional electronic skin mediated by dopamine-modified carbon nanotubes and gelatin was fabricated. In this work, a flexible, conductive, and biocompatible adhesive hydrogel was prepared directly without further processing by simply mixing dopamine-modified carbon nanotubes, gelatin, and acrylamide. Carbon nanotubes play a dominant role in the electromechanical and mechanical properties of the hydrogel. The polydopamine gives the hydrogel good and reproducible adhesion properties. At the same time, the hydrogels obtained have good sensing properties and can detect mechanically conducted signals of human motion. In addition, the hydrogels are able to act as conductive media to deliver electrical stimuli generated by poly(vinylidene fluoride-trifluoroethylene) piezoelectric membranes to accelerate wound healing. In conclusion, this work provides a feasible method to prepare hydrogel sensors with good biocompatibility, good mechanical properties, and good adhesion, which can be widely used in human motion detection, smart skin, and electrical stimulation therapy.

Facile Double-Injection Strategy for the Engineering of Versatile Multiresponsive Hydrogels Encapsulating Drug-Loaded Micelles for Promoting Diabetic Wound Healing

“…The FTIR spectra (Figure S1) of APBA also confirmed the grafting of PBA onto ALG. Gelatin is the main component of animal skin, bone, muscle membrane, and other connective tissues, which is partially hydrolyzed from animal collagen with a cell adhesion site structure . As a natural water-soluble biodegradable polymer, Gel has good biocompatibility, and its degradation products are easily absorbed.…”

“…Gelatin is the main component of animal skin, bone, muscle membrane, and other connective tissues, which is partially hydrolyzed from animal collagen with a cell adhesion site structure. 23 As a natural watersoluble biodegradable polymer, Gel has good biocompatibility, and its degradation products are easily absorbed. Accordingly, adoption of gelatin as the second structural network of hydrogel can provide bionic components and an environment for the wound surface.…”

The latest research progress of conductive hydrogels in the field of electrophysiological signal acquisition

“…The prepared hydrogels not only have excellent freezing resistance (−30 °C), long-term moisturization, and excellent sensitivity, but can also be used as strain sensors for detecting various human motions as well as electrodes for human electrophysiological signal acquisition. Along the same line, Yu et al 84 modified carbon nanotubes (CNTs) using polydopamine (PDA) and introduced the modified PDA-CNTs into a hydrogel network composed of polyacrylamide and gelatin (Fig. 3c).…”

Perspectives on recent advancements in energy harvesting, sensing and bio-medical applications of piezoelectric gels

“…Such emerging advantages of PiezoGels offer an alternative to conventional electrical stimulation devices and encourage their use in new therapeutic applications such as chronic wound healing, disease diagnosis, and potential bio-clinical treatments. 279–282…”