Development of a Flexible and Wearable Microelectrode Array Patch Using a Screen-Printed Masking Technique for Accelerated Wound Healing
Harish Gnanasambanthan, Debashis Maji
Abstract
Effective wound care management system demands the emergence of smart bandages with wound healing techniques. Electrical stimulation (ES)-based wound healing has shown excellent results in faster wound closure by mimicking the endogenous electric field naturally produced at the sight of a wound and assisting the same. The present work highlights the development of a flexible copper-based micro-electrode array (MEA) patch over a polyimide substrate for triggering ES-induced accelerated wound healing for applied DC potentials only. Simulation results highlight the ES optimization for varying maximum DC potentials of 0.2, 0.4, and 1.0 V toward the generation of effective electric field-induced electrotaxis. A simulated patch was fabricated using a unique screen-printed masking technique involving the use of polyvinyl chloride (PVC) ink as a masking material over a copper polyimide film to realize the MEA structures. An integrated pH sensor was also fabricated using screen printing of Ag/AgCl ink over the same to monitor in situ blood pH levels. The developed low-cost MEA patches showed good electrical continuity as well as excellent flexibility and skin conformality. It was thereafter mounted over an 8 mm diameter cutaneous wound on a rat model, and appropriate ES was applied as per the simulation data. Post-healing results were visually verified as well as examined for histological changes in tissue cross-sections, and an excellent correlation between the simulation findings and visual observations was obtained. A significant reduction in the healing time was achieved (9 days) through this study for an optimized DC potential of 0.4 V, unlike the control samples, which took 13 days for healing. The results also mimicked the natural endogenous potential, thereby clearly demonstrating the effectiveness of the fabricated patch toward accelerated wound healing.