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Bio/ecoresorbable electronic systems create unique opportunities in implantable medical devices that serve a need over a finite time period and then disappear naturally to eliminate the need for extraction surgeries. A critical challenge in the development of this type of technology is in materials that can serve as thin, stable barriers to surrounding ground water or biofluids, yet ultimately dissolve completely to benign end products. This paper describes a class of inorganic material (silicon oxynitride, SiON) that can be formed in thin films by plasma‐enhanced chemical vapor deposition for this purpose. In vitro studies suggest that SiON and its dissolution products are biocompatible, indicating the potential for its use in implantable devices. A facile process to fabricate flexible, wafer‐scale multilayer films bypasses limitations associated with the mechanical fragility of inorganic thin films. Systematic computational, analytical, and experimental studies highlight the essential materials aspects. Demonstrations in wireless light‐emitting diodes both in vitro and in vivo illustrate the practical use of these materials strategies. The ability to select degradation rates and water permeability through fine tuning of chemical compositions and thicknesses provides the opportunity to obtain a range of functional lifetimes to meet different application requirements.

3D, hierarchical micro/nanostructures formed with advanced functional materials are of growing interest due to their broad potential utility in electronics, robotics, battery technology, and biomedical engineering. Among various strategies in 3D micro/nanofabrication, a set of methods based on compressive buckling offers wide‐ranging material compatibility, fabrication scalability, and precise process control. Previously reports on this type of approach rely on a single, planar prestretched elastomeric platform to transform thin‐film precursors with 2D layouts into 3D architectures. The simple planar configuration of bonding sites between these precursors and their assembly substrates prevents the realization of certain types of complex 3D geometries. In this paper, a set of hierarchical assembly concepts is reported that leverage multiple layers of prestretched elastomeric substrates to induce not only compressive buckling of 2D precursors bonded to them but also of themselves, thereby creating 3D mesostructures mounted at multiple levels of 3D frameworks with complex, elaborate configurations. Control over strains used in these processes provides reversible access to multiple different 3D layouts in a given structure. Examples to demonstrate these ideas through both experimental and computational results span vertically aligned helices to closed 3D cages, selected for their relevance to 3D conformal bio‐interfaces and multifunctional microsystems.