Laser Micro/Nano Fabrication of Electrochemical Filtering Capacitors: Multiscale Structural Engineering for High‐Frequency Power Conditioning

Abstract Electrochemical capacitors are highly promising for alternating current (AC) line filtering in miniaturized electronic devices due to their ability to store charge at the interface, thereby overcoming the limitations of traditional capacitors. Nonetheless, challenges persist in attaining high‐frequency response and minimizing ripple effects with existing manufacturing methods. As integrated circuits become more compact, there is a pressing need for higher areal capacitance density. Laser fabrication techniques, with their high precision and adaptability, are suitable for producing micro‐supercapacitors (MSCs). However, the slow transport of ions and electrons within these devices increases internal resistance and impairs rapid response, presenting a significant obstacle. This review evaluates various equivalent circuit models and governing equations relevant to filtering circuits, establishing a basis for enhancing performance through structural and material optimization. Recent advancements in laser‐assisted fabrication—including material synthesis, precise scribing, and flexible device production—show potential for increasing capacitance and decreasing resistance. Future research should focus on developing high‐precision MSCs, optimizing laser‐controlled electrolyte distribution, and refining collector processing techniques. These improvements are crucial for developing high‐performance, compact filtering solutions suitable for fast electronic systems and demanding technological applications.