Cleanroom-Free Toolkit for Patterning Submicron-Resolution Bioelectronics on Flexibles.

Fabricating flexible bioelectronics remains an ongoing challenge in pursuing a cost-effective, efficient, scalable, and environmentally friendly approach for research and commercial applications. The current dominant method, lithography, presents challenges due to its incompatibility with solvent-sensitive biomaterials and the phase mismatch between the photoresist and flexible substrates, such as elastomers. This study proposes a simplified, cleanroom-free toolkit as a potential alternative to lithography for fabricating intricate bioelectronics on flexible substrates with submicron resolution. This technique integrates a two-photon laser writing mask, mask transfer, and multi-layer/material patterning processes, enabling batch-to-batch processing and making it suitable for scalable production. With excellent conformal patterning capability, different functional and encapsulation biomaterials can be patterned on flexible substrates, including elastomers, parylene-C, polymer sheets, skin, fabric, and plant leaves. The versatility of this toolkit is validated by fabricating various prototypes of wearable and implantable bioelectronics, demonstrating excellent performance.