Yamada Shunsuke, Toshiyoshi Hiroshi
Research Organization for Nano & Life Innovation, Waseda University, 3-4-1 Ookubo, Shinjuku, Tokyo 169-8555, Japan.
Institute of Industrial Science (IIS), The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
ACS Appl Mater Interfaces. 2020 Aug 12;12(32):36449-36457. doi: 10.1021/acsami.0c10229. Epub 2020 Jul 24.
In the era of a trillion sensors, a tremendous number of sensors will be consumed to collect information for big data analysis. Once they are installed in a harsh environment or implanted in a human/animal body, we cannot easily retrieve the sensors; the sensors for these applications are left unattended but expected to decay after use. In this paper, a disposable temperature sensor that disappears with contact with water is reported. The gel electrolyte based on an ionic liquid and a water-soluble polymer, so-called ionic gel, exhibits a Young's modulus of 96 kPa, which is compatible with human muscle, skin, and organs, and can be a wearable device or in soft robotics. A study on electrical characteristics of the sensor with various temperatures reveals that the ionic conductivity and capacitance increased by 12 times and 4.8 times, respectively, when the temperature varies from 30 to 80 °C. The temperature sensor exhibits a short response time of 1.4 s, allowing real-time monitoring of temperature change. Furthermore, sensors in an array format can obtain the spatial distribution of temperature. The developed sensor was found to fully dissolve in water in 16 h. The water-dissolvability enables practical applications including healthcare, artificial intelligence, and environmental sensing.
在万亿传感器时代，将消耗大量传感器来收集信息用于大数据分析。一旦它们被安装在恶劣环境中或植入人体/动物体内，我们就无法轻易取回传感器；这些应用中的传感器无人值守，但预计在使用后会自行降解。本文报道了一种与水接触后会消失的一次性温度传感器。基于离子液体和水溶性聚合物的凝胶电解质，即所谓的离子凝胶，其杨氏模量为96 kPa，与人体肌肉、皮肤和器官相兼容，可作为可穿戴设备或用于软机器人技术。对该传感器在不同温度下的电学特性研究表明，当温度从30℃变化到80℃时，离子电导率和电容分别增加了12倍和4.8倍。该温度传感器的响应时间短至1.4 s，能够实时监测温度变化。此外，阵列形式的传感器可以获取温度的空间分布。已发现所开发的传感器在16小时内可完全溶解于水中。这种水溶性使其能够应用于医疗保健、人工智能和环境传感等实际领域。
