Simulation and Fabrication of Micro-Electrode Arrays for Electrical Stimulation Induced Wound Healing

Abstract

Chronic wound care has always been a major challenge for healthcare professionals and is a significant public health crisis. Electrical stimulation (ES) therapy is an effective alternative treatment for chronic and acute dermal wounds by promoting electrotaxis of different types of cells during different stages of wound healing. In the present work, a simulation of guided electrotaxis through external ES was carried out using 2D and 3D finite element analysis of a wound model. Initial simulation work was performed using COMSOL Multiphysics 5.3 ®which highlighted the efficacy of micro-electrode arrays (MEAs) compared to the conventional two-electrode system. Further design optimization includes the incorporation of a gap between the electrode surface and wound bed to achieve an optimal EF gradient of ~140-200 mV/mm at the wound periphery, along with reduced electrical spikes and uniform EF distribution for effective electrotaxis. This study also highlights strategies for fabricating a flexible and conformal aluminum thin-film MEA patch over a polydimethylsiloxane (PDMS) elastomer using the thermal evaporation technique through a stencil mask. A novel technique for stress-free self-release of the fabricated electrode was adopted using a polyvinyl alcohol (PVA) sacrificial layer to realize a crack-free electrically continuous patterned structure. Furthermore, an initial ES study over agar-based phantoms was also carried out, which gave promising results by faithfully reproducing input-applied signals. The present initial investigation could therefore be used to develop a wound-healing bandage that could accelerate wound healing through electrical stimulation.

Keywords

• Agar phantom study
• electrical stimulation therapy
• electro-taxis
• micro-electrode array (MEAs)
• flexible MEA patch