Ono Nahoko, Seishima Ryo, Shigeta Kohei, Okabayashi Koji, 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 Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
Small. 2024 Jun;20(24):e2400938. doi: 10.1002/smll.202400938. Epub 2024 Mar 15.
Mechanoresponsive materials have been studied to visualize and measure stresses in various fields. However, the high-sensitive and spatiotemporal imaging remain a challenging issue. In particular, the time evolutional responsiveness is not easily integrated in mechanoresponsive materials. In the present study, high-sensitive spatiotemporal imaging of weak compression stresses is achieved by time-evolutional controlled diffusion processes using conjugated polymer, capsule, and sponge. Stimuli-responsive polydiacetylene (PDA) is coated inside a sponge. A mechanoresponsive capsule is set on the top face of the sponge. When compression stresses in the range of 6.67-533 kPa are applied to the device, the blue color of PDA is changed to red by the diffusion of the interior liquid containing a guest polymer flowed out of the disrupted capsule. The applied strength (F/N), time (t/s), and impulse (F·t/N s) are visualized and quantified by the red-color intensity. When a guest metal ion is intercalated in the layered structure of PDA to tune the responsivity, the device visualizes the elapsed time (τ/min) after unloading the stresses. PDA, capsule, and sponge play the important roles to achieve the time evolutional responsiveness for the high-sensitive spatiotemporal distribution imaging through the controlled diffusion processes.
人们已经对机械响应材料进行了研究，以可视化和测量各个领域中的应力。然而，高灵敏度的时空成像仍然是一个具有挑战性的问题。特别是，时间演化响应性不容易整合到机械响应材料中。在本研究中，通过使用共轭聚合物、胶囊和海绵的时间演化控制扩散过程，实现了对弱压缩应力的高灵敏度时空成像。刺激响应性聚二乙炔（PDA）涂覆在海绵内部。一个机械响应胶囊设置在海绵的顶面上。当对该装置施加6.67-533kPa范围内的压缩应力时，由于含有客体聚合物的内部液体从破裂的胶囊中流出并扩散，PDA的蓝色会变为红色。施加的强度（F/N）、时间（t/s）和冲量（F·t/N s）通过红色强度进行可视化和量化。当客体金属离子插入PDA的层状结构中以调节响应性时，该装置可以可视化卸载应力后的经过时间（τ/min）。PDA、胶囊和海绵通过控制扩散过程，在实现高灵敏度时空分布成像的时间演化响应性方面发挥着重要作用。
