Laser-matter interactions in intrinsically soft materials for biointegrated systems

Abstract Biointegrated systems are emerging as a new class of technology that redefines how electronic devices interact with the human body and surrounding environments through intimate integration with biological tissues. To establish such interfaces, intrinsically soft materials, including liquid metals, conducting polymers, hydrogels, elastomers, and composites, have attracted significant attention because their low modulus minimizes mechanical mismatch with soft tissues. However, conventional fabrication strategies are often incompatible with intrinsically soft materials due to harsh processing conditions. In this regard, laser processing has emerged as a powerful manufacturing strategy for soft biointegrated systems by delivering highly localized and programmable energy with exceptional spatial and temporal precision. Depending on the laser-matter interaction mechanism, laser irradiation can induce localized heating, structural reconfiguration, chemical conversion, and interfacial reconstruction within soft materials. In this article, we explore the fundamental mechanisms of two representative laser-matter interactions, photothermal and photochemical. Then we deal with laser processing strategies for soft materials, followed by representative biointegrated systems enabled by laser-based approaches. Finally, we discuss current challenges and future opportunities for scalable, adaptive, and intelligent biointegrated systems. Collectively, these discussions highlight the emerging role of laser processing in tailoring structural properties and generating conductive functionalities in intrinsically soft biointegrated systems.