Suk‐Won Hwang

A remarkable feature of modern silicon electronics is its ability to remain physically invariant, almost indefinitely for practical purposes. Although this characteristic is a hallmark of applications of integrated circuits that exist today, there might be opportunities for systems that offer the opposite behavior, such as implantable devices that function for medically useful time frames but then completely disappear via resorption by the body. We report a set of materials, manufacturing scheme

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 capabiliti

Transient electronics represents an emerging class of technology that exploits materials and/or device constructs that are capable of physically disappearing or disintegrating in a controlled manner at programmed rates or times. Inorganic semiconductor nanomaterials such as silicon nanomembranes/nanoribbons provide attractive choices for active elements in transistors, diodes and other essential components of overall systems that dissolve completely by hydrolysis in biofluids or groundwater. We

Abstract 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

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 wi

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 depende

Personal accessories such as glasses and watches that we usually carry in our daily life can yield useful information from the human body, yet most of them are limited to exercise-related parameters or simple heart rates. Since these restricted characteristics might arise from interfaces between the body and items as one of the main reasons, an interface design considering such a factor can provide us with biologically meaningful data. Here, we describe three-dimensional-printed, personalized, m

Materials and device designs are presented for electronic systems that undergo functional transformation by a controlled time sequence in the dissolution of active materials and/or encapsulation layers. Demonstration examples include various biocompatible, multifunctional systems with autonomous behavior defined by materials selection and layout.

A strategy of materials synthesis, characteristic evaluations, and manufacturing process for a mechanically elastic, biologically safe silicon-based dopamine detector that is designed to be completely transient, i.e., dissolved in water and/or biofluids, potentially in the brain after a desired period of operation, is introduced. Use of inexpensive, bioresorbable iron (Fe)-based nanoparticles (NPs) is one of the attractive choices for efficient catalytic oxidation of dopamine as an alternative f

We introduce optimized elastomeric conductive electrodes using a mixture of silver nanowires (AgNWs) with carbon nanotubes/polydimethylsiloxane (CNTs/PDMS), to build a portable earphone type of wearable system that is designed to enable recording electrophysiological activities as well as listening to music at the same time. A custom-built, plastic frame integrated with soft, deformable fabric-based memory foam of earmuffs facilitates essential electronic components, such as conductive elastomer

New options in the material context of transient electronics are essential to create or expand potential applications and to progress in the face of technological challenges. A soft, transparent, and cost-effective polymer of levan polysaccharide that is capable of complete, programmable dissolution is described when immersed in water and implanted in an animal model. The results include chemical analysis, the kinetics of hydrolysis, and adjustable dissolution rates of levan, and a simple theore

The lifetime of transient electronic components can be programmed via the use of encapsulation/passivation layers or of on-demand, stimuli-responsive polymers (heat, light, or chemicals), but yet most research is limited to slow dissolution rate, hazardous constituents, or byproducts, or complicated synthesis of reactants. Here we present a physicochemical destruction system with dissolvable, nontoxic materials as an efficient, multipurpose platform, where chemically produced bubbles rapidly col

Current research in the area of surgical mesh implants is somewhat limited to traditional designs and synthesis of various mesh materials, whereas meshes with multiple functions may be an effective approach to address long-standing challenges including postoperative complications. Herein, a bioresorbable electronic surgical mesh is presented that offers high mechanical strength over extended timeframes, wireless post-operative pressure monitoring, and on-demand drug delivery for the restoration

Abstract Effective encapsulation is essential for reliable operation of bio‐integrated electronics, particularly those containing dissolvable elements, under humid environments for desired periods of time; however, conventional inorganic or organic encapsulants often suffer from tissue‐incompatible mechanical rigidity and insufficient water‐barrier performance. Here, a mechanically resilient and efficient encapsulation strategy is proposed that can exceed a functional lifetime of state‐of‐the‐ar