Donghee Son

Implantable endovascular devices such as bare metal, drug eluting, and bioresorbable stents have transformed interventional care by providing continuous structural and mechanical support to many peripheral, neural, and coronary arteries affected by blockage. Although effective in achieving immediate restoration of blood flow, the long-term re-endothelialization and inflammation induced by mechanical stents are difficult to diagnose or treat. Here we present nanomaterial designs and integration s

Large-scale colloidal synthesis and integration of uniform-sized molybdenum disulfide (MoS₂ ) nanosheets for a flexible resistive random access memory (RRAM) array are presented. RRAM using MoS₂ nanosheets shows a ≈10 000 times higher on/off ratio than that based on exfoliated MoS₂ . The good uniformity of the MoS₂ nanosheets allows wafer-scale system integration of the RRAM array with pressure sensors and quantum-dot light-emitting diodes.

Skin-inspired wearable electronic/biomedical systems based on functional nanomaterials with exceptional electrical and mechanical properties have revolutionized wearable applications, such as portable Internet of Things, personalized healthcare monitors, human-machine interfaces, and even always-connected precise medicine systems. Despite these advancements, including the ability to predict and to control nanolevel phenomena of functional nanomaterials precisely and strategies for integrating na

Strategies for efficient charge confinement in nanocrystal floating gates to realize high-performance memory devices have been investigated intensively. However, few studies have reported nanoscale experimental validations of charge confinement in closely packed uniform nanocrystals and related device performance characterization. Furthermore, the system-level integration of the resulting devices with wearable silicon electronics has not yet been realized. We introduce a wearable, fully multiple

Electronics for wearable applications require soft, flexible, and stretchable materials and designs to overcome the mechanical mismatch between the human body and devices. A key requirement for such wearable electronics is reliable operation with high performance and robustness during various deformations induced by motions. Here, we present materials and device design strategies for the core elements of wearable electronics, such as transistors, charge-trap floating-gate memory units, and vario

Both self-healable conductors and stretchable conductors have been previously reported. However, it is still difficult to simultaneously achieve high stretchability, high conductivity, and self-healability. Here, we observed an intriguing phenomenon, termed "electrical self-boosting", which enables reconstructing of electrically percolative pathways in an ultrastretchable and self-healable nanocomposite conductor (over 1700% strain). The autonomously reconstructed percolative pathways were direc

Soft neuroprosthetics that monitor signals from sensory neurons and deliver motor information can potentially replace damaged nerves. However, achieving long-term stability of devices interfacing peripheral nerves is challenging, since dynamic mechanical deformations in peripheral nerves cause material degradation in devices. Here, a durable and fatigue-resistant soft neuroprosthetic device is reported for bidirectional signaling on peripheral nerves. The neuroprosthetic device is made of a nano

Contemporary implantable bioelectronic devices are typically made of high-quality metals and inorganic materials. However, their rigid and flat nature, especially in their bulk state, pose critical challenges for long-term signal monitoring and feedback stimulation in vivo because of the following issues: (i) nonconformal contact with the tissue surface, (ii) mechanical modulus mismatch at the biotic-abiotic interface, and (iii) chronic immune response and potential inflammatory reactions. There

Abstract Implantable biosensors and wearable bioelectronics need to be intimately interfaced with soft human tissues for a high‐quality health diagnosis and feedback therapy. Despite the recent developments in these devices, it is essential to further enhance their performance and functionalities in order to facilitate the formation of intimate interfaces between the devices and the human body. This will help minimize the unwanted injuries to target tissues, enhance the efficiency of sensing and

We developed a nanoneedle transistor-based sensor (NTS) for the selective detection of calcium ions inside a living cell. In this work, a single-walled carbon nanotube-based field effect transistor (swCNT-FET) was first fabricated at the end of a glass nanopipette and functionalized with Fluo-4-AM probe dye. The selective binding of calcium ions onto the dye molecules altered the charge state of the dye molecules, resulting in the change of the source-drain current of the swCNT-FET as well as th

Abstract Advances in electronic textiles (E‐textiles) for next‐generation wearable electronics have originated from making a balance between electrical and mechanical properties of stretchy conductive fibers. Despite such progress, the trade‐off issue is still a challenge when individual fibers are woven and/or stretched undesirably. Time‐consuming fiber weaving has limited practical uses in scalable E‐textiles. Here, a facile method is presented to fabricate ultra‐stretchable Ag nanoparticles (