Multiangle, self-powered sensor array for monitoring head impacts.

Mild concussions occur frequently and may come with long-term cognitive, affective, and physical sequelae. However, the diagnosis of mild concussions lacks objective assessment and portable monitoring techniques. Here, we propose a multiangle self-powered sensor array for real-time monitoring of head impact to further assist in clinical analysis and prevention of mild concussions. The array uses triboelectric nanogenerator technology, which converts impact force from multiple directions into electrical signals. With an average sensitivity of 0.214 volts per kilopascal, a response time of 30 milliseconds, and a minimum resolution of 1.415 kilopascals, the sensors exhibit excellent sensing capability over a range of 0 to 200 kilopascals. Furthermore, the array enables reconstructed head impact mapping and injury grade assessment via a prewarning system. By gathering standardized data, we expect to build a big data platform that will permit in-depth research of the direct and indirect effects between head impacts and mild concussions in the future.

Self-Powered High-Voltage Recharging System for Removing Noxious Tobacco Smoke by Biomimetic Hairy-Contact Triboelectric Nanogenerator.

The most common size range of particulate matter (PM) in tobacco smoke is 1.0 to 5.0 microns; however, a high number of the most harmful PM is as small as 0.5 micron that is a serious threat to human health, and it is difficult to remove. There is an urgent need to develop a new purification technology for high-efficiency removing tobacco smoke with easily construction and low cost. Here, a method of self-powered high-voltage recharging system is demonstrated by designing biomimetic hairy-contact triboelectric nanogenerator (BHC-TENG) for long-lasting adsorption with a wide range from PM 0.5 to PM 10. The open-circuit voltage of BHC-TENGs reaches 8.42 KV, which can continuously charge injection to the melt-blown fabric, whose surface potential is able to maintain nearly 260 V level and create a uniform electrostatic adsorption field on the surface. This high-voltage recharging system reduces the concentration of PMs to World Health Organization (WHO) standards, maintaining the purification efficiency of PM 0.5- PM 10 persistently over 90%.

Active-Sensing Epidermal Stretchable Bioelectronic Patch for Noninvasive, Conformal, and Wireless Tendon Monitoring.

Sensors capable of monitoring dynamic mechanics of tendons throughout a body in real time could bring systematic information about a human body's physical condition, which is beneficial for avoiding muscle injury, checking hereditary muscle atrophy, and so on. However, the development of such sensors has been hindered by the requirement of superior portability, high resolution, and superb conformability. Here, we present a wearable and stretchable bioelectronic patch for detecting tendon activities. It is made up of a piezoelectric material, systematically optimized from architectures and mechanics, and exhibits a high resolution of 5.8 × 10-5 N with a linearity parameter of R 2 = 0.999. Additionally, a tendon real-time monitoring and healthcare system is established by integrating the patch with a micro controller unit (MCU), which is able to process collected data and deliver feedback for exercise evaluation. Specifically, through the patch on the ankle, we measured the maximum force on the Achilles tendon during jumping which is about 16312 N, which is much higher than that during normal walking (3208 N) and running (5909 N). This work not only provides a strategy for facile monitoring of the variation of the tendon throughout the body but also throws light on the profound comprehension of human activities.