Flexible intelligent array patch based on synergy of polyurethane and nanofiber for sensitive monitor and smart treatment

Currently, the implantation and health treatment of electronic devices based on adhesion and flexible substrates are widely studied. However, achieving stable electrical conductivity on flexible and adhesive substrates remains challenging. Here, a flexible intelligent array patch based on the synergism of polyurethane (PU) and nanofibers (NFs) is fabricated for sensitive monitoring and intelligent treatment. Polycaprolactone-gelatin NFs are first deposited on the PU film by electrospinning to form a PU/NF substrate, then a conductive gold layer in a pattern of electrode modules and circuits was sputtered on the substrate through self-designed mask. Finally, the sensor electrodes and drug electrodes were fabricated and integrated to realize a loop feedback system. Compared with sputtering the gold layer directly on the PU, the PU/NF substrate with nano-network enables excellent elasticity and stable electrical conductivity, owing to the fact that the PU and NF layers are mechanically matched and tightly bonded, which improves sensor sensitivity and eliminates artifacts. The strain sensor constructed using gold coated PU/NF can respond quickly within 0.15 s and detect even 0.1% tiny strain, which collects subtle physiological signals. The drug electrode was prepared on gold coated NF/PU substrate by electroplating polypyrrole and simultaneously loading dexamethasone (DEX). The drug electrode with a low-impedance, high-specific surface area can controllably release 54.9 μg cm−2 within 1 min at 0.6 V, which is about 35 times higher than that of flat glass. It is demonstrated that this system can work on isolated porcine and in vivo rat heart models for cardiac signal detection and drug release.