Self-healing hydrogel electrodes from ingestible materials

Abstract: Mechanically robust self-healing conducting hydrogel offer new possibilities to further the state of the art of ingestible (edible) device research. Here, we report self-healing hydrogel electrodes based on readily available ingestible materials sourced from supermarkets. We used an interpenetrating polymer network hydrogel consisting of sodium tetraborate-crosslinked poly(vinyl acetate) and food-grade gelatin that exhibited synergistic strengthening enabling it to withstand the stresses similar to those experienced in the gastrointestinal tract. The edible gels achieved full self-healing within 1 min (electrical conductivity 8.8 ± 0.8 mS/cm) and 1 h (tensile strength 60 ± 5 kPa), respectively, of reconnection of two severed halves. Graphic Abstract: [Figure not available: see fulltext.].