Researchers at Shinshu University successfully recorded previously unexplained behavior of hydrogel microspheres (microgels) using a newly customized tool: temperature-controlled high-speed atomic force microscopy (TC HS AFM). This machine, which is the only one in the world, was assembled by Dr. Takayuki Uchihashi of Nagoya University to investigate proteins. It was applied for the first time to the study of microgels by the team at Daisuke Suzuki Laboratory, Graduate School of Textile Science & Technology and RISM (Research Initiative for Supra-Materials) of Shinshu University. The study lead by first year doctoral candidate, Yuichiro Nishizawa, succeeded in observing the structure of the microgels which had been difficult due to limitations of previous equipment.
The structure of microgels has been studied extensively using scattering and imaging techniques including electron microscopy, fluorescence microscopy, atomic force microscopy, and super-resolution microscopy. The thermoresponsive properties of the core-shell structures had been well documented using such techniques. Using TC HS AFM, they were able to observe and record the particles in detail, non-thermoresponsive inhomogeneous decanano-scale spherical domains, which had been hypothesized by Dr. Kenji Urayama of the Kyoto Institute of Technology.