Structural Engineering of Inorganic Materials for Skin-Integrated Deformable Bioelectronics

Abstract

Traditional inorganic semiconductor bioelectronics, while offering exceptional electronic performance, suffer from inherent mechanical brittleness that hinders seamless, low-impedance conformal integration with the soft, dynamic, and curvilinear surfaces of human skin. To address this mechanical mismatch, this review comprehensively examines structural engineering strategies designed to achieve biomimetic stretchability and compliance. We systematically analyze two-dimensional and three-dimensional structural designs including wavy, fractal, serpentine, kirigami, and noncoplanar architectures that effectively decouple structural stretchability from the intrinsic material strains. Beyond geometric patterning, we investigate the recent paradigm shift toward heterogeneous integration and multi-network composite materials. In particular, we highlight the synergistic combination of soft elastomeric matrices with conductive nanomaterials, such as silver nanowires, MXenes, and carbon-based nanomaterials, to establish durable and selectively stretchable conductive pathways under severe multi-axial deformation. Furthermore, the role of self-healable, tissue-conformable double-network hydrogels is discussed as a promising medium to minimize sensor-skin interface impedance, suppress motion artifacts, and provide long-term biocompatibility. Finally, we showcase the multi-vital applications of these compliant bioelectronic platforms, ranging from high-fidelity electrophysiological recording (ECG, EMG, and EEG) to continuous sweat-biomarker monitoring and thermal energy harvesting. By offering a multi-scale design perspective from interface mechanics to active clinical sensing, this review provides a robust guideline for designing next-generation skin-conformal bioelectronics, steering the future of closed-loop healthcare systems and human-machine interfaces.