Nakamitsu Minami, Oyama Keigo, Imai Hiroaki, Fujii Syuji, Oaki Yuya
Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan.
Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka, 535-8585, Japan.
Adv Mater. 2021 Apr;33(14):e2008755. doi: 10.1002/adma.202008755. Epub 2021 Feb 22.
Measurement of mechanical stresses, such as compression, shear, and tensile stresses, contributes toward achieving a safer and healthier life. In particular, the detection of weak compression stresses is required for healthcare monitoring and biomedical applications. Compression stresses in the order of 10 -10 Pa have been visualized and/or quantified using mechano-responsive materials in previous works. However, in general, it is not easy to detect compression stresses weaker than 10 Pa using conventional mechano-responsive materials because the dynamic motion of the rigid mechano-responsive molecules is not induced by such a weak stress. In the present work, weak compression stresses in the order of 10 -10 Pa are visualized and measured via the integration of stimuli-responsive materials, such as layered polydiacetylene (PDA) and dry liquid (DL), through response cascades. DLs consisting of liquid droplets covered by solid particles release the interior liquid and collapse with application of a weak compression stress. The color of the layered PDA is changed by the spilled liquid as a chemical stress. A variety of weak compression stresses, such as expiratory pressure, are visualized and colorimetrically measured using the paper-based device of the integrated stimuli-responsive materials. Diverse mechano-sensing devices can be designed via the integration of stimuli-responsive materials.
测量诸如压缩、剪切和拉伸应力等机械应力有助于实现更安全、更健康的生活。特别是，医疗监测和生物医学应用需要检测微弱的压缩应力。在先前的工作中，已经使用机械响应材料对10 -10 帕量级的压缩应力进行了可视化和/或量化。然而，一般来说，使用传统的机械响应材料检测低于10 帕的压缩应力并不容易，因为如此微弱的应力不会引起刚性机械响应分子的动态运动。在本工作中，通过刺激响应材料（如层状聚二乙炔（PDA）和干液（DL））的集成，通过响应级联对10 -10 帕量级的微弱压缩应力进行了可视化和测量。由被固体颗粒覆盖的液滴组成的DLs在施加微弱压缩应力时会释放内部液体并坍塌。层状PDA的颜色会因溢出的液体作为化学应力而改变。使用集成刺激响应材料的纸质装置可以对各种微弱压缩应力（如呼气压力）进行可视化和比色测量。通过刺激响应材料的集成可以设计出各种机械传感装置。
