Hollow MXene Sphere-Based Flexible E-Skin for Multiplex Tactile Detection.

Skin-like electronics that can provide comprehensively tactile sensing is required for applications such as soft robotics, health monitoring, medical treatment, and human-machine interfaces. In particular, the capacity to monitor the contact parameters such as the magnitude, direction, and contact location of external forces is crucial for skin-like tactile sensing devices. Herein, a flexible electronic skin which can measure and discriminate the contact parameters in real time is designed. It is fabricated by integrating the three-dimensional (3D) hollow MXene spheres/Ag NW hybrid nanocomposite-based embedded stretchable electrodes and T-ZnOw/PDMS film-based capacitive pressure sensors. To the best of our knowledge, it is the first stretchable electrode to utilize the 3D hollow MXene spheres with the essential characteristic, which can effectively avoid the drawbacks of stress concentration and shedding of the conductive layer. The strain-resistance module and the pressure-capacitance module show the excellent sensing performance in stability and response time, respectively. Moreover, a 6 × 6 sensor array is used as a demonstration to prove that it can realize the multiplex detection of random external force stimuli without mutual interference, illustrating its potential applications in biomimetic soft wearable devices, object recognition, and robotic manipulation.

Eggshell membrane-templated synthesis of 3D hierarchical porous Au networks for electrochemical nonenzymatic glucose sensor.

Sensitive and accurate test of blood glucose levels is necessary to monitor and prevent diabetic complications. Herein, we developed a novel and sensitive non-enzymatic glucose sensing platform by employing 3D hierarchical porous Au networks (HPANs) as electrocatalyst for glucose oxidization. The HPANs were prepared through a bio-inspired synthesis method, in which the natural eggshell membrane (ESM) was introduced as template. The structure and properties of the as-prepared HPANs were characterized by a set of techniques, including scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD) and cyclic voltammetry (CV). The HPANs showed high catalytic activity towards glucose oxidization due to the unique structure. Inspiringly, the HPANs-based electrochemical glucose sensor could be driven at low potential (+0.1V) and showed an outstanding performance for glucose determination with two linear ranges of 1-500µM and 4.0-12mM, a limit of detection (LOD) of 0.2µM (3σ), and fast response time (less than 2s). Moreover, the stability and anti-interference performance of developed sensor was also excellent, enabling its preliminary application in clinical sample (human serum) test. Significantly, this work offered an environmentally friendly method for fabricating 3D nanostructure by using ESM (a biowaste) as template, setting up a typical example for producing new value-added nanomaterials with sensing application.