Design of a DNA‐Based Double Network Hydrogel for Electronic Skin Applications

Abstract Electronic skin (e‐skin) is widely studied for its ability to detect physiological information and provide feedback through electrical signals. Biocompatible stimulus‐responsive DNA‐based hydrogels exhibit high sensitivity, which makes them outstanding candidates for biomedical applications. However, several disadvantages, such as weak mechanical properties, expensive manufacturing costs, cumbersome double chain design, and difficulty obtaining bulk size, seriously limit their practical application. Based on the double network (DN) strategy, a universal, low‐cost, and high‐toughness deoxyribonucleic acid/poly( N ‐hydroxyethyl acrylamide) (DNA/pHEAA) DN hydrogel is designed. The transparent hydrogel shows tensile stress/strain of 0.96 ± 0.043 MPa/2537.55 ± 23.24%, rapid self‐recovery ability (peak stress/energy dissipation recovery rate of 99.72%/95.38% after 30 s resting), excellent fatigue resistance (peak stress/energy dissipation retention rate of 91.08%/81.05% after 100 loading‐unloading cycles with strain of 50%), reversible adhesive ability (≈45 KPa), and good biocompatibility. Thus, the DNA/pHEAA DN hydrogel can be used as an e‐skin. Sensing signals are displayed on a smartphone as images sent through wireless technology; the images change with the collected signals, achieving motion detection. The universal and low‐cost design of stimulus‐responsive DNA‐based hydrogels with high toughness, excellent self‐recovery, and anti‐fatigue performance is expected to promote their application in the biomedical field.