A remarkable feature of modern silicon electronics is its ability to remain functionally and physically invariant, almost indefinitely for many practical purposes. Here, we introduce a silicon-based technology that offers the opposite behavior: it gradually vanishes over time, in a well-controlled, programmed manner. Devices that are ‘transient’ in this sense create application possibilities that cannot be addressed with conventional electronics, such as active implants that exist for medically useful timeframes, but then completely dissolve and disappear via resorption by the body. We report a comprehensive set of materials, manufacturing schemes, device components and theoretical design tools for a complementary metal oxide semiconductor (CMOS) electronics of this type, together with four different classes of sensors and actuators in addressable arrays, two options for power supply and a wireless control strategy. A transient silicon device capable of delivering thermal therapy in an implantable mode and its demonstration in animal models illustrate a system-level example of this technology.

Materials and fabrication approaches that allow integration of biodegradable/transient electronics onto diverse classes of biodegradable substrates are presented in this article. By first depositing, patterning, and etching the materials for the electronics and then integrating them on a substrate of interest, it is possible to use nearly any type of biodegradable material for this purpose. Component and system‐level studies of various devices and biodegradable polymers illustrate the capabilities and operational aspects. Dissolution studies and mechanics modeling results highlight different modes for transient behavior.

Materials and fabrication procedures are described for bioresorbable transistors and simple integrated circuits, in which the key processing steps occur on silicon wafer substrates, in schemes compatible with methods used in conventional microelectronics. The approach relies on an unusual type of silicon on insulator wafer to yield devices that exploit ultrathin sheets of monocrystalline silicon for the semiconductor, thin films of magnesium for the electrodes and interconnects, silicon dioxide and magnesium oxide for the dielectrics, and silk for the substrates. A range of component examples with detailed measurements of their electrical characteristics and dissolution properties illustrate the capabilities. In vivo toxicity tests demonstrate biocompatibility in sub‐dermal implants. The results have significance for broad classes of water‐soluble, “transient” electronic devices.

Single-crystalline silicon nanomembranes (Si NMs) represent a critically important class of material for high-performance forms of electronics that are capable of complete, controlled dissolution when immersed in water and/or biofluids, sometimes referred to as a type of "transient" electronics. The results reported here include the kinetics of hydrolysis of Si NMs in biofluids and various aqueous solutions through a range of relevant pH values, ionic concentrations and temperatures, and dependence on dopant types and concentrations. In vitro and in vivo investigations of Si NMs and other transient electronic materials demonstrate biocompatibility and bioresorption, thereby suggesting potential for envisioned applications in active, biodegradable electronic implants.

Materials, device designs and manufacturing approaches are presented for classes of RF electronic components that are capable of complete dissolution in water or biofluids. All individual passive/active components as well as system-level examples such as wireless RF energy harvesting circuits exploit active materials that are biocompatible. The results provide diverse building blocks for physically transient forms of electronics, of particular potential value in bioresorbable medical implants with wireless power transmission and communication capabilities.