Precise control of the life cycle of materials has become critical. Long-lasting materials are not always the best—for example, nondegradable plastic waste is now a serious environmental problem. Transient electronic devices have a prescribed life cycle in which all or part of the device can physically dissolve, disappear, or degrade after their utility ends. This concept creates compelling opportunities for biodegradable temporary, implantable electronics that do not require removal; environmentally benign biodegradable electronics with zero waste; and security hardware with on-time system destruction. Nanoscale materials provide new uses for transient materials dissolution by scaling up the rate of degradation; for example, a microscale Si single crystal is not dissoluble, but at around 100 nm, the Si single crystal dissolves in approximately one month. Significant advances have been made in exploring transient, water-soluble, and biodegradable nano-/micromaterials, and their degradation chemistry and kinetics. Advancing the state of the art in transient electronics requires contributions from many disciplines of materials science ranging from materials analysis to applications. This article outlines the history of transient electronics and briefly overviews concepts and issues from inorganic- and organic-based electronic materials, process technology, and energy devices to trigger transient electronics.

Electronic devices have revolutionized society’s trajectories within, and interactions with, the world. The skin on our bodies holds incredible functionalities, such as stretchability and degradability, which only recently are being explored for electronic systems and have the potential to revolutionize device applications and disposal. Polymeric materials are especially poised to realize stretchable and transient electronics. In this article, strategies are reviewed for synthesizing and utilizing biodegradable and elastomeric organic materials, followed by component-specific materials approaches and examples of assembled stretchable and transient systems. Stretchable and biodegradable organic electronic devices will call upon intersections of different fields, which promise to open up new frontiers for electronics in the biomedical, exploratory, sensory, and consumer electronics fields.

Transient electronic systems represent an emerging class of technology defined by an ability to physically dissolve, sublime, chemically degrade, disintegrate, or transform in a controlled manner, either spontaneously or through a trigger event. Bioresorbable (or, equivalently, bioabsorbable) electronic devices, as a subset of transient technologies, are designed to undergo complete dissolution when immersed in biofluids. Applications include temporary implants and other medical devices that serve important purposes in diagnostics and therapies, but with finite lifetimes matched to those of natural biological processes such as wound healing. Here, transience by bioresorption eliminates the devices without a trace, thereby bypassing the costs, complications, and risks associated with secondary surgical procedures for device retrieval. Such systems demand complete sets of bioresorbable electronic materials, including semiconductors, dielectrics, and conductors, as the fundamental building blocks for functional components. The considerations are not only in electronic performance, but in degradation chemistry and biocompatibility of both the materials and the products of their reactions with biofluids. This article highlights recent progress in this area of materials science and describes some of the most sophisticated bioresorbable electronic systems that combine these materials with bioresorbable polymers, the biomedical applications of these devices, and some directions for future work.

Transient electronics represents recent technology that can partially or completely degrade, dissolve, or disintegrate under certain conditions in actively and passively controlled ways. They offer applications as eco-friendly alternatives to existing electronic components, implantable biomedical devices, and software/hardware protection systems. The degradable characteristics of materials and circuits, however, lead to various fabrication issues and difficulties in manufacturing complex systems requiring fine and elaborate design layouts and microfabrication procedures under thermally and chemically harsh conditions. Identifying advanced materials and the development of manufacturing processes compatible with established transient materials have been conducted for several years to address these issues. In this article, we focus on recent trends in manufacturing technologies for transient electronic systems, including direct fabrication of electronics on transient substrates using organic–inorganic electronic materials, screen-printing approaches particularly for conductive traces, microfabrication combined with multiple transfer-printing techniques, and large-scale, foundry-compatible technologies.

Transient energy supply remains one of the key challenges limiting the development of transient implantable medical devices for monitoring, diagnosis, and treatment of diseases within a predetermined time frame. A key feature of such devices is their controllable degradation during service life. An on-board transient energy supply with predictable performance over time is required to drive transient electronics. In this article, we present recent advances in the development of materials for biodegradable energy-storage devices (batteries and supercapacitors) and biodegradable energy-harvesting systems (enzymatic biofuel cells and triboelectric nanogenerators). Future perspectives, challenges, and opportunities related to energy materials for transient power sources will also be summarized.

Emerging transient electronics capable of complete physical and chemical disintegration are derived from advanced materials and device design strategies. The area of exploring on-demand smart transient electronics has seen continuous development, allowing for the degradation process to be triggered or controlled through an instantaneous stimulus, thus offering significant potential in data security, undetectable spying, and bioresorbable electronics applications. In this article, we summarize recent progress in the design and strategies of on-demand smart transient electronics and emphasize the basic principles of selecting, processing, and integrating materials. After an introduction to the history and properties of triggered transient electronics, we discuss on-demand smart transient electronics based on their triggering stimuli, strategies for designing thermal, optical, or electrical triggers, and future development trends and challenges.

Self-assembly techniques are powerful and efficient methods for the synthesis of nanoscale materials. Using these techniques and their combination with other bottom-up fabrication processes, materials with hierarchical features can be produced with form and function in multiple length scales. We synthesize multifunctional nanoparticles through surfactant-assisted noncovalent interactions using nanoparticle building blocks. Self-assembly of these nano-building blocks results in functional materials that exhibit well-defined morphologies and hierarchical architectures for a wide range of applications. Hierarchically structured porphyrin nanocrystals can be synthesized through surfactant micelle-confined noncovalent interactions of photoactive porphyrins. We can amplify the intrinsic advantages of individual photoactive porphyrins by engineering them into well-defined active nanostructures. Through kinetic control, these nanocrystals exhibit precisely defined size, shape, and spatial arrangement of the individual porphyrins, which facilitates intermolecular mass and energy transfer. These self-assembly techniques provide remarkable flexibility to design morphologies and architectures that produce desirable properties for practical applications including photocatalysis, photodegradation, and phototherapy.