Large‐Scale and Cost‐Effective Fabrication of Ultra‐Thin, Biodegradable Microelectrode Arrays and Pressure Sensors Using Laser Micromachining

ABSTRACT This paper addresses the critical need for innovative fabrication strategies to advance wearable and implantable medical devices, emphasizing versatility, cost‐effectiveness, scalability, and large‐scale manufacturability. Specifically, the focus is on bioresorbable electronic devices like microelectrode arrays (MEAs), crucial for intracerebral neural recording and electrical stimulation, and implantable pressure sensors necessitating flexible and cytocompatible properties to enhance tissue compliance and minimize the risk of rejection. Traditional cleanroom‐based techniques have limitations in compatibility with most of the bioresorbable materials. To overcome this challenge, a mask‐free, contact‐less, and scalable fabrication strategy utilizing an advanced UV‐based laser system is proposed. The approach successfully demonstrates fabrication of flexible, cytocompatible, and biodegradable MEAs and pressure sensors. A biodegradable substrate is prepared using cost‐effective and transparent biodegradable material, i.e., chitosan, with biodegradable Zinc (Zn) electrodes. Electrochemical impedance spectroscopy (EIS) analysis reveals an impedance of 10 kΩ at 1 kHz. Also, as‐prepared chitosan exhibits good tensile strength and excellent cytocompatibility with smart muscle cells, demonstrating its suitability for implantable applications. The manufactured MEAs exhibit excellent stability under multiple bending angles, proving their reliable performance when interfacing with tissues. Furthermore, the fabricated electrodes are fully degraded in less than 2 days in phosphate‐buffered saline (PBS) solution, demonstrating excellent biodegradability.