Jeong Sook Ha

Wearable biosensors that continuously monitor physiological and biochemical stress signals are essential for understanding acute and chronic stress responses. Conventional wearable sensors often suffer from mechanical damage, unstable skin adhesion, and limited durability of biochemical sensing, which undermine long‐term reliability. Here, we report a fully self‐healing wearable biosensing system that integrates a laser‐induced graphene (LIG) strain sensor, a molecularly imprinted polymer (MIP) cortisol sensor, microfluidic channels with cross‐hatch patterned fillers, a catechol‐functionalized polyurethane (CF‐PU) adhesive, and an oxime‐carbamate bond‐based polyurethane (OC‐PU) encapsulation layer for simultaneous monitoring of pulse signals and sweat cortisol levels. The LIG‐based strain sensor provides pulse waveforms, while the MIP‐based cortisol sensor enables selective detection of cortisol in human sweat, achieving a detection limit of 10 pM. The microfluidic channels ensure continuous sweat collection and delivery to the sensing interface, and the CF‐PU adhesive maintains skin attachment in the presence of sweat. This system maintains reliable biosignal acquisition under repeated cycles of mechanical damage and self‐healing at 65°C for 6 h, as well as prolonged operation. As a result, the system enables non‐invasive monitoring of physiological and biochemical stress markers after mechanical damage and offers a fully self‐healing stress‐monitoring platform for next‐generation health applications.

SWCNT-embedded Si–C composites offer enhanced structural integrity and internal conductivity, enabling stable operation with high areal capacity and long-term cycling performance for practical lithium-ion battery applications.

Currently reported wearable sensors based on soft polymeric materials are vulnerable to mechanical damage but rarely achieve rapid repair, reliable multimodal readout, and low crosstalk. We report a fully self‐healing dual‐mode sensor patch based on newly synthesized vitrimer‐like self‐healing elastomer (V‐SHE) with an integrated liquid metal Joule heater. V‐SHE enables rapid self‐healing via thermal heating at near body temperature of 40°C in 30 min, owing to incorporation of both associative and dissociative dynamic bonds into the hydrogen bond‐rich polymer backbone and further reinforcement with an epoxide crosslinker. A dual‐mode sensor fabricated with PEDOT:PSS/CNT coated microporous V‐SHE foam allows recovery of performance over repetitive cycles of cut/ thermal healing as well as interference‐free, simultaneous pressure and temperature sensing, with self‐powered operation via Seebeck transduction. Furthermore, on‐demand much faster self‐healing within 5 min is enabled by the liquid metal‐based Joule heater. This work demonstrates the potential application of our fast self‐healing dual‐mode sensor with a Joule heater to future highly durable and deformable electronics with longevity.

The transport of anions across cell membranes is difficult because of the negatively charged outer surfaces of cell membranes. To overcome this limitation, herein, we report a system for transporting aromatic anions across cellular membranes via self-assembly using a synthetic imidazolium-fused aromatic amphiphile. The amphiphile with cationic and aromatic groups in close proximity to each other could interact with anionic pyranine via electrostatic and aromatic interactions to form supramolecular vesicles. Supramolecular vesicles based on the synthetic imidazolium-fused aromatic amphiphile and pyranine complex transport anionic aromatic pyranine across the membranes of live MCF-7 cells without cytotoxicity.

There is a growing need for research on self‐healing materials capable of spontaneously repairing physical damage, allowing the fabrication of highly durable wearable devices featuring flexibility and stretchability. Herein, the study reports on the fabrication of a novel, magnetically aligning, fully and rapidly self‐healing skin‐attachable biosensor based on newly synthesized photothermally self‐healing polyurethane. By introducing photothermal amine‐capped aniline trimers to selectively self‐healable polyurethane, the synthesized self‐healing polymer achieves a fast and high recovery rate of 81.1% from complete bisection upon laser irradiation for just 3 min. Additionally, a thin‐film type strain sensor fabricated via the spray patterning of liquid metal EGaIn as an electrode onto the surface of the self‐healing polymer exhibits a high sensitivity to strain from deformation, enabling the real‐time monitoring of bio‐signals. Furthermore, the integration of a magnetic aligning layer directly patterned and embedded onto the self‐healing polymer enhances the self‐healing performance of the sensor after damage by 4.3 times on average, compared to when using manual alignment. In short, this work demonstrates a high‐performance fully self‐healing electronic device via the synthesis of novel fast self‐healing photothermal polymers and the introduction of patterned liquid metal electrodes and magnetic alignment layers.

A novel self‐healing and antifreezing/antidrying conductive eutectohydrogel, ideal for wearable multifunctional sensors and supercapacitors, is reported. Conductive eutectohydrogel with self‐healing and facilely tunable mechanical performance is obtained by incorporation of trehalose and phytic acid as reversible cross‐linkers into a polyacrylamide network, forming the dynamic hydrogen bonding and electrostatic interactions. Furthermore, combined use of deep eutectic solvent with water ensures the air stability as well as the antifreezing/antidrying characteristics. The synthesized eutectohydrogel exhibits a self‐healing efficiency of 90.7% after 24 h at room temperature, Young's modulus of 140.9 kPa, and strain at break of 352.8%. With the eutectohydrogel as a versatile platform, self‐healing strain and temperature sensors, electrocardiogram electrodes, and supercapacitor are fabricated, recovering the device performance after self‐healing from complete bisection and exhibiting stable performance over a wide temperature range from −20 to 50 °C. With a vertically integrated patch device of supercapacitor and strain sensor attached onto skin, various body movements are successfully detected using the energy stored in the supercapacitor, without performance degradation even after self‐healing from complete bisection of the full patch device. This work demonstrates high potential application of the synthesized eutectohydrogel to flexible wearable devices featuring durability and longevity.

Molecular self-assembly can trigger or regulate specific chemical reactions that would otherwise be infeasible when molecules exist individually. Supramolecular structures can significantly affect the rate of chemical reactions; therefore, optimizing supramolecular structures by manipulating intermolecular interactions is crucial for achieving the desired reactivity. Melamine is known to form hydrogen bonds with cyanuric acid, resulting in the formation of a supramolecular network. Melarsomine, an effective medication for heartworm treatment in dogs, contains a melamine moiety. It has yet to be studied how the chemical stability of melarsomine is affected by its interaction with other molecules. Herein, we report the formation of a two-dimensional supramolecular network between melarsomine and cyanuric acid via hydrogen bonds. This network structure captures dissolved oxygen in an aqueous solution, accelerating the oxidative degradation of melarsomine.

A fully self‐healing sensor patch consisting of an in‐plane integrated dual‐mode sensor and a pressure sensor with a vertically integrated electrocardiogram (ECG) electrode is reported. For a full‐device self‐healing, interlayer self‐bonding by using self‐healing oxime‐carbamate bond‐based polyurethane and room temperature self‐healing TUEG₃ capped Au nanosheet (T‐Au NS) electrodes are devised. Via the use of a self‐healing sensor foam prepared by a coating of a self‐healing composite of polyurethane and polyaniline onto a microporous graphene foam, a self‐healing dual‐mode sensor is fabricated to detect the pressure and temperature simultaneously without interference. Furthermore, the interdigitated self‐healing electrode of T‐Au NS is applied to the pressure sensor to enhance the sensitivity up to 208.62 kPa⁻¹ (<1 kPa), enabling the detection of small pulse signals even after multiple self‐healing events. By using the common self‐healing T‐Au NS electrode vertically integrated onto the sensor patch, ECG signals are also detected. With this sensor patch, skin temperature, wrist pulse, and ECG signals are successfully detected after a simultaneous full‐device self‐healing from complete bisection. This study demonstrates the facile fabrication of a high‐performance, fully self‐healing patch of multi‐sensors via the deliberate selection of sensor design and the associated functional materials, confirming its high potential applicability to highly durable health monitoring systems.

Most supramolecular systems were discovered by using a trial-and-error approach, leading to numerous synthetic efforts to obtain optimal supramolecular building blocks for selective guest encapsulation. Here, we report a simple coassembly strategy for preparing tamoxifen-selective supramolecular nanomaterials in an aqueous solution. The synthetic amphiphile molecule, 1,1,2,2-tetraphenylethylene (TPE), promotes large tamoxifen aggregate disassembly into smaller, discrete aggregates such as ribbon-like and micellar assemblies in coassembled solutions, enhancing the solubility and dispersion. The TPE moiety exhibits enhanced emission upon tamoxifen interaction, enabling the observation of the coassembled species in an aqueous solution for cell imaging. The tamoxifen-selective fluorescent micelles in the presence of a 1:1 molar ratio of TPE derivative with tamoxifen show enhanced tamoxifen absorption and anticancer effects against MCF-7 breast cancer cells. These supramolecular approaches, based on the coassembly of building blocks with molecular structural similarity, can provide a novel strategy for the efficient development of selective molecular carriers with enhanced biological activities.