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Abstract The cost‐effective and scalable synthesis and patterning of soft nanomaterial composites with improved electrical conductivity and mechanical stretchability remains challenging in wearable devices. This work reports a scalable, low‐cost fabrication approach to directly create and pattern crumpled porous graphene/NiS₂nanocomposites with high mechanical stretchability and electrical conductivity through laser irradiation combined with electrodeposition and a pre‐strain strategy. With modulated mechanical stretchability and electrical conductivity, the crumpled graphene/NiS₂nanocomposite can be readily patterned into target geometries for application in a standalone stretchable sensing platform. By leveraging the electrical energy harvested from the kinetic motion from wearable triboelectric nanogenerator (TENG) and stored in micro‐supercapacitor arrays (MSCAs) to drive biophysical sensors, the system is demonstrated to monitor human motions, body temperature, and toxic gas in the exposed environment. The material selections, design strategies, and fabrication approaches from this study provide functional nanomaterial composites with tunable properties for future high‐performance bio‐integrated electronics. 

Abstract Although continuous and non‐invasive measurements of sweat biomarkers may provide vital health information, sweat collection often involves intense physical activities or chemical/thermal stimuli. The natural body sweat during endogenous metabolic or stress processes, secreted at much lower rates at rest, may be continuously analyzed using microfluidic devices integrated with hydrophilic rigid fillers; however, the sweat uptake and accumulation in thermoregulatory processes take too long for near‐real‐time measurements. This work provides an innovative body fluid collection strategy using a granular hydrogel scaffold (GHS), facilitating osmotic and capillary effects to uptake and transfer an ultralow amount of sweat into a microfluidic device at rest. Taken together with a spiral microfluidic channel, the GHS‐embedded microfluidics reduce the evaporation of collected sweat and store it in a sensing well for near‐real‐time measurements. Integrating the sweat‐collecting system with an enzymatic gold‐graphene nanocomposite‐modified laser‐induced graphene (LIG) electrode and a LIG‐based pH sensor enables the accurate continuous on‐body detection of sweat lactate during normal daily activities at a low perspiration rate. The novel combination of a GHS‐integrated microfluidic system with a low‐cost, flexible, sensitive, and stable LIG‐based sensing system provides an accessible technology for sweat‐based biosensing during normal daily activities. 

Abstract Nanomaterial‐based stretchable electronics composed of conductive nanomaterials in elastomer can seamlessly integrate with human skin to imperceptibly capture electrophysiological signals. Despite the use of transfer printing to form embedded structures, it remains challenging to facilely and stably integrate conductive nanomaterials with thin, low‐modulus, adhesive elastomers. Here, a facile‐yet‐simple laser‐induced graphene (LIG)‐assisted patterning and transfer method is demonstrated to integrate patterned silver nanowires onto an ultra‐low modulus silicone adhesive as ultra‐conformal epidermal electrodes. The resulting thin epidermal electrodes of ≈50 µm exhibit a low sheet resistance (0.781 Ω sq⁻¹), tissue‐like Young's modulus (0.53 MPa), strong self‐adhesion, and excellent breathability. The breathable electrodes dynamically conformed to the skin with low contact impedance allow for long‐term, high‐fidelity monitoring of electrophysiological signals in complex environments (even during exercise and heavy sweating). Moreover, the LIG‐assisted transfer can provide a robust interface to establish a stable connection between the soft electrodes and rigid hardware. The large‐scale fabrication further provides an eight‐channel electromyography system combined with a deep learning algorithm for gesture classification and recognition with remarkable accuracy (95.4%). The results from this study also provide design guidelines and fabrication methods of the next‐generation epidermal electronics for long‐term dynamic health monitoring, prosthetic control, and human‐robot collaborations. 

Abstract Stretchable triboelectric nanogenerators (TENGs) represent a new class of energy‐harvesting devices for powering wearable devices. However, most of them are associated with poor stretchability, low stability, and limited substrate material choices. This work presents the design and demonstration of highly stretchable and stable TENGs based on liquid metalel ectrodes with different phases. The conductive and fluidic properties of eutectic gallium‐indium (EGaIn) in the serpentine microfluidic channel ensure the robust performance of the EGaIn‐based TENG upon stretching over several hundred percent. The bi‐phasic EGaIn (bGaIn) from oxidation lowers surface tension and increases adhesion for printing on diverse substrates with high output performance parameters. The optimization of the electrode shapes in the bGaIn‐based TENGs can reduce the device footprint and weight, while enhancing stretchability. The applications of the EGaIn‐ and bGaIn‐based TENG include smart elastic bands for human movement monitoring and smart carpets with integrated data transmission/processing modules for headcount monitoring/control. Combining the concept of origami in the paper‐based bGaIn TENG can reduce the device footprint to improve output performance per unit area. The integration of bGaIn‐TENG on a self‐healing polymer substrate with corrosion resistance against acidic and alkaline solutions further facilitates its use in various challenging and extreme environments. 

Abstract Silk nanofibers (SNFs) from abundant sources are low‐cost and environmentally friendly. Combined with other functional materials, SNFs can help create bioelectronics with excellent biocompatibility without environmental concerns. However, it is still challenging to construct an SNF‐based composite with high conductivity, flexibility, and mechanical strength for all SNF‐based electronics. Herein, this work reports the design and fabrication of Ti₃C₂Tx‐silver@silk nanofibers (Ti3C2Tx‐Ag@SNF) composites with multi‐dimensional heterogeneous conductive networks using combined in situ growth and vacuum filtration methods. The ultrahigh electrical conductivity of Ti₃C₂T_x‐Ag@SNF composites (142959 S m⁻¹) provides the kirigami‐patterned soft heaters with a rapid heating rate of 87 °C s⁻¹. The multi‐dimensional heterogeneous network further allows the creation of electromagnetic interference shielding devices with an exceptionally high specific shielding effectiveness of 10,088 dB cm⁻¹. Besides working as a triboelectric layer to harvest the mechanical energy and recognize the hand gesture, the Ti₃C₂T_x‐Ag@SNF composites can also be combined with an ionic layer to result in a capacitive pressure sensor with a high sensitivity of 410 kPa⁻¹in a large range due to electronic‐double layer effect. The applications of the Ti₃C₂T_x‐Ag@SNF composites in recognizing human gestures and human‐machine interfaces to wirelessly control a trolley demonstrate the future development of all SNF‐based electronics. 

Abstract The erratic, intermittent, and unpredictable nature of sweat production, resulting from physiological or psychological fluctuations, poses intricacies to consistently and accurately sample and evaluate sweat biomarkers. Skin‐interfaced microfluidic devices that rely on colorimetric mechanisms for semi‐quantitative detection are particularly susceptible to these inaccuracies due to variations in sweat secretion rate or instantaneous volume. This work introduces a skin‐interfaced colorimetric bifluidic sweat device with two synchronous channels to quantify sweat rate and biomarkers in real‐time, even during uncertain sweat activities. In the proposed bifluidic‐distance metric approach, with one channel to measure sweat rate and quantify collected sweat volume, the other channel can provide an accurate analysis of the biomarkers based on the collected sweat volume. The closed channel design also reduces evaporation and resists contamination from the external environment. The feasibility of the device is highlighted in a proof‐of‐the‐concept demonstration to analyze sweat chloride for evaluating hydration status and sweat glucose for assessing glucose levels. The low‐cost yet highly accurate device provides opportunities for clinical sweat analysis and disease screening in remote and low‐resource settings. The developed device platform can be facilely adapted for the other biomarkers when corresponding colorimetric reagents are exploited. 

Abstract Skin‐interfaced high‐sensitive biosensing systems to detect electrophysiological and biochemical signals have shown great potential in personal health monitoring and disease management. However, the integration of 3D porous nanostructures for improved sensitivity and various functional composites for signal transduction/processing/transmission often relies on different materials and complex fabrication processes, leading to weak interfaces prone to failure upon fatigue or mechanical deformations. The integrated system also needs additional adhesive to strongly conform to the human skin, which can also cause irritation, alignment issues, and motion artifacts. This work introduces a skin‐attachable, reprogrammable, multifunctional, adhesive device patch fabricated by simple and low‐cost laser scribing of an adhesive composite with polyimide powders and amine‐based ethoxylated polyethylenimine dispersed in the silicone elastomer. The obtained laser‐induced graphene in the adhesive composite can be further selectively functionalized with conductive nanomaterials or enzymes for enhanced electrical conductivity or selective sensing of various sweat biomarkers. The possible combination of the sensors for real‐time biofluid analysis and electrophysiological signal monitoring with RF energy harvesting and communication promises a standalone stretchable adhesive device platform based on the same material system and fabrication process. 

Abstract General movements (GMs) have been widely used for the early clinical evaluation of infant brain development, allowing immediate evaluation of potential development disorders and timely rehabilitation. The infants’ general movements can be captured digitally, but the lack of quantitative assessment and well‐trained clinical pediatricians presents an obstacle for many years to achieve wider deployment, especially in low‐resource settings. There is a high potential to explore wearable sensors for movement analysis due to outstanding privacy, low cost, and easy‐to‐use features. This work presents a sparse sensor network with soft wireless IMU devices (SWDs) for automatic early evaluation of general movements in infants. The sparse network consisting of only five sensor nodes (SWDs) with robust mechanical properties and excellent biocompatibility continuously and stably captures full‐body motion data. The proof‐of‐the‐concept clinical testing with 23 infants showcases outstanding performance in recognizing neonatal activities, confirming the reliability of the system. Taken together with a tiny machine learning algorithm, the system can automatically identify risky infants based on the GMs, with an accuracy of up to 100% (99.9%). The wearable sparse sensor network with an artificial intelligence‐based algorithm facilitates intelligent evaluation of infant brain development and early diagnosis of development disorders. 

Abstract Although increasing efforts have been devoted to the development of non‐invasive wearable electrochemical sweat sensors for monitoring physiological and metabolic information, most of them still suffer from poor stability and specificity over time and fluctuating temperatures. This study reports the design and fabrication of a long‐term stable and highly sensitive flexible electrochemical sensor based on nanocomposite‐modified porous graphene by facile laser treatment for detecting biomarkers such as glucose in sweat. The laser‐reduced and patterned stable conductive nanocomposite on the porous graphene electrode provides the resulting glucose sensor with an excellent sensitivity of 1317.69 µA mm⁻¹cm⁻²and an ultra‐low limit of detection of 0.079 µm. The sensor can also detect pH and exhibit extraordinary stability to maintain more than 91% sensitivity over 21 days in ambient conditions. Taken together with a temperature sensor based on the same material system, the dual glucose and pH sensor integrated with a flexible microfluidic sweat sampling network further results in accurate continuous on‐body glucose detection calibrated by the simultaneously measured pH and temperature. The low‐cost, highly sensitive, and long‐term stable platform could facilitate the early identification and continuous monitoring of different biomarkers for non‐invasive disease diagnosis and treatment evaluation.