Development of a Flexible and Wearable Microelectrode Array Patch Using a Screen-Printed Masking Technique for Accelerated Wound Healing

Effective wound care management system demands the emergenceofsmart bandages with wound healing techniques. Electrical stimulation(ES)-based wound healing has shown excellent results in faster woundclosure by mimicking the endogenous electric field naturally producedat the sight of a wound and assisting the same. The present work highlightsthe development of a flexible copper-based micro-electrode array (MEA)patch over a polyimide substrate for triggering ES-induced acceleratedwound healing for applied DC potentials only. Simulation results highlightthe ES optimization for varying maximum DC potentials of 0.2, 0.4,and 1.0 V toward the generation of effective electric field-inducedelectrotaxis. A simulated patch was fabricated using a unique screen-printedmasking technique involving the use of polyvinyl chloride (PVC) inkas a masking material over a copper polyimide film to realize theMEA structures. An integrated pH sensor was also fabricated usingscreen printing of Ag/AgCl ink over the same to monitor in situ bloodpH levels. The developed low-cost MEA patches showed good electricalcontinuity as well as excellent flexibility and skin conformality.It was thereafter mounted over an 8 mm diameter cutaneous wound ona rat model, and appropriate ES was applied as per the simulationdata. Post-healing results were visually verified as well as examinedfor histological changes in tissue cross-sections, and an excellentcorrelation between the simulation findings and visual observationswas 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 resultsalso mimicked the natural endogenous potential, thereby clearly demonstratingthe effectiveness of the fabricated patch toward accelerated woundhealing.