Laser Processed Flexible Electronics

The demand for flexible electronic devices has been increasing, mostly driven by the emerging markets of consumable electronics and the Internet of Things (IoT). Among several processing techniques, Direct Laser Writing (DLW) has been regarded as an alternative to conventional microelectronics manufacturing processes. DLW is a cost-effective, one-step, and mask-less technique enabling the production of flexible electronics for a variety of applications, such as PCB boards and other components.[1–3] Using laser processes, different materials and devices can be directly synthesized through precursors chemical reduction, or even the production of graphene through the conversion of carbon-based substrates, such as paper and cork.[1, 3, 4]<br/><br/>This work presents the capabilities and versatility of DLW writing for electronic components development. By this method were obtained silver, copper, and graphene conductive tracks exhibiting sheet resistances of 0.23 ohm.sq^-1, 0.53 ohm.sq^-1,and 30 ohm.sq^-1, respectively. These conductive layers led to the production of radio-frequency antennas, micro-supercapacitors, and simple circuits on paper and cork, further demonstrating the relevance of this method. This technique is compatible with a set of recyclable and bio-compatible substrates, adding a layer of sustainability to the production method.[1–3, 5] Finally, DLW was also applied to synthesize metal oxide semiconductors (WO₃, ZnO, among others) broadening the prospect of fabricating sensors and other devices through this direct and simple technique.<br/><br/>References<br/><br/>1. Coelho J, Correia RF, Silvestre S, et al (2022) Paper-based laser-induced graphene for sustainable and flexible microsupercapacitor applications. Microchim Acta 2022 1901 190:1–10. https://doi.org/10.1007/S00604-022-05610-0<br/>2. Pinheiro T, Silvestre S, Coelho J, et al (2021) Laser-Induced Graphene on Paper toward Efficient Fabrication of Flexible, Planar Electrodes for Electrochemical Sensing. Adv Mater Interfaces 8:2101502. https://doi.org/10.1002/admi.202101502<br/>3. Silvestre SL, Pinheiro T, Marques AC, et al (2022) Cork derived laser-induced graphene for sustainable green electronics. Flex Print Electron 7:035021. https://doi.org/10.1088/2058-8585/ac8e7b<br/>4. Chyan Y, Ye R, Li Y, et al (2018) Laser-Induced Graphene by Multiple Lasing: Toward Electronics on Cloth, Paper, and Food. ACS Nano 12:2176–2183. https://doi.org/10.1021/acsnano.7b08539<br/>5. Correia R, Deuermeier J, Correia MR, et al (2022) Biocompatible Parylene-C Laser-Induced Graphene Electrodes for Microsupercapacitor Applications. ACS Appl Mater Interfaces 14:46427–46438. https://doi.org/10.1021/acsami.2c09667