Highly Uniform, Flexible Microelectrodes Based on the Clean Single-Walled Carbon Nanotube Thin Film with High Electrochemical Activity

Application and Progress of Chemometrics in Voltammetric Biosensing

The voltammetric electrochemical sensing method combined with biosensors and multi-sensor systems can quickly, accurately, and reliably analyze the concentration of the main analyte and the overall characteristics of complex samples. Simultaneously, the high-dimensional voltammogram contains the rich electrochemical features of the detected substances. Chemometric methods are important tools for mining valuable information from voltammetric data. Chemometrics can aid voltammetric biosensor calibration and multi-element detection in complex matrix conditions. This review introduces the voltammetric analysis techniques commonly used in the research of voltammetric biosensor and electronic tongues. Then, the research on optimizing voltammetric biosensor results using classical chemometrics is summarized. At the same time, the incorporation of machine learning and deep learning has brought new opportunities to further improve the detection performance of biosensors in complex samples. Finally, smartphones connected with miniaturized voltammetric biosensors and chemometric methods provide a high-quality portable analysis platform that shows great potential in point-of-care testing.

Fully Soft Pressure Sensor Based on Bionic Spine-Pillar Structure for Robotics Motion Monitoring

Soft and stretchable sensors are essential to the development of electronic skin, especially their potential applications in health care and intelligent robots, which have increasingly attracted attentions. Herein, inspired by the epidermal tissue hierarchy, we propose a high-sensitivity fully soft capacitive pressure sensor with bionic spine-pillar microstructure. Benefiting from the combination of the random microscale spines and the millimeter-sized pillar array prepared based on polydimethylsiloxane, the proposed sensor exhibits a well deformability, a high sensitivity up to 2.87 k/Pa at low-pressure range, and a broad linear pressure dynamic range from 5 Pa to 100 kPa. A simple equivalent circuit model was established to demonstrate the sensing mechanism and geometric effect. For practical application demonstrations, the sensor was utilized to monitor local subtle and large movements of the skin, such as finger bending, wrist bending, swallowing, and facial muscle movements. The sensor shows a conformality with human skin to follow the skin extension closely. Furthermore, the proposed sensing strategy can provide a distinguishable tactile feedback for controlling robot arm and soft claw in various tasks, illustrating its potential applications in robotics.

Advanced Soft Materials, Sensor Integrations, and Applications of Wearable Flexible Hybrid Electronics in Healthcare, Energy, and Environment

Recent advances in soft materials and system integration technologies have provided a unique opportunity to design various types of wearable flexible hybrid electronics (WFHE) for advanced human healthcare and human-machine interfaces. The hybrid integration of soft and biocompatible materials with miniaturized wireless wearable systems is undoubtedly an attractive prospect in the sense that the successful device performance requires high degrees of mechanical flexibility, sensing capability, and user-friendly simplicity. Here, the most up-to-date materials, sensors, and system-packaging technologies to develop advanced WFHE are provided. Details of mechanical, electrical, physicochemical, and biocompatible properties are discussed with integrated sensor applications in healthcare, energy, and environment. In addition, limitations of the current materials are discussed, as well as key challenges and the future direction of WFHE. Collectively, an all-inclusive review of the newly developed WFHE along with a summary of imperative requirements of material properties, sensor capabilities, electronics performance, and skin integrations is provided.