Ultra-thin crystalline silicon stands as a cornerstone material in the foundation of modern micro and nano electronics. Despite the proliferation of various materials including oxide-based, polymer-based, carbon-based, and two-dimensional (2D) materials, crystal silicon continues to maintain its stronghold, owing to its superior functionality, scalability, stability, reliability, and uniformity. Nonetheless, the inherent rigidity of the bulk silicon leads to incompatibility with soft tissues, hindering the utilization amid biomedical applications. Because of such issues, decades of research have enabled successful utilization of various techniques to precisely control the thickness and morphology of silicon layers at the scale of several nanometres. This review provides a comprehensive exploration on the features of ultra-thin single crystalline silicon as a semiconducting material, and its role especially among the frontier of advanced bioelectronics. Key processes that enable the transition of rigid silicon to flexible form factors are exhibited, in accordance with their chronological sequence. The inspected stages span both prior and subsequent to transferring the silicon membrane, categorized respectively as on-wafer manufacturing and rigid-to-soft integration. Extensive guidelines to unlock the full potential of flexible electronics are provided through ordered analysis of each manufacturing procedure, the latest findings of biomedical applications, along with practical perspectives for researchers and manufacturers.

High-entropy ceramics exhibit novel intrinsic properties. Hence, they have been explored for a wide range of applications ranging from thermal insulation and energy storage to advanced optical components. Recently, the semiconductor industry has faced a demand for higher-performance chips, necessitating higher aspect ratios in wafer fabrication and further miniaturization of linewidths. Therefore, novel materials with high plasma etching resistance and minimal contaminant generation are needed. The plasma-etching resistance displayed by high-entropy ceramics can be an innovative solution to this emerging challenge. In this study, we successfully fabricated single-phase high-entropy sesquioxide ceramics with high optical transparency, dense microstructure, and minimal residual pores. A structural analysis of the fabricated samples revealed a single-phase structure with excellent phase homogeneity. An evaluation of the plasma-etching resistance of high-entropy ceramics revealed for the first time a low etching rate of 8 nm/h compared with that of conventional plasma-resistant materials. These comprehensive characterizations of high-entropy ceramics indicate that they are promising candidates for significantly improving the production yield of semiconductors and for a wide range of potential applications, such as next-generation active optical ceramics.