"Molecular Mechatronics" is a concept that integrates "Molecular", "Mechanics", and "Electronics". It is an interdisciplinary research field that seeks to create new materials, devices, and technologies at the interfaces of these fields, with the aim of transforming and advancing existing materials and technologies. We develop innovative electroactive organic and polymeric materials and device technologies for applications including haptic feedback devices for virtual reality (VR), micro-vibration energy harvesters, and stress, friction, optical, and molecular sensors (see Figure). Based on the synthesis of uniquely designed molecular materials, we precisely control hierarchical ordered structures and their organization across length scales ranging from nanometers to centimeters. Through this structural control, we aim to achieve high-speed transport of ions, electrons, photons, and matter, as well as efficient energy conversion, ultimately creating high-performance energy-conversion devices such as actuators that convert electrical energy into mechanical energy. We develop a wide range of self-assembled materials, including ion-active nanostructured liquid crystals, liquid-crystalline semiconductors incorporating electronically active π-conjugated structures, and block copolymers capable of forming electrets. Our research also encompasses flexible metal–organic framework (MOF) materials, flexible thin films of covalent organic frameworks (COFs) exhibiting ionic and electronic conductivity, thermoplastic low-molecular-weight physical gels, and natural polysaccharide-based polymer gels. Our group conducts integrated research and development spanning the entire process from molecular design and synthesis of materials to structural and physical-property characterization, circuit design, and device fabrication and evaluation. We also place strong emphasis on operando structural analysis using synchrotron radiation facilities and on elucidating device operating mechanisms through computational science. Researchers in our group can acquire a broad range of experimental and analytical techniques, including organic and polymer synthesis, chromatography, nuclear magnetic resonance (NMR) spectroscopy including pulsed-field-gradient measurements for ion diffusion, thermal analysis, fluorescence spectroscopy, electrochemical impedance spectroscopy, dielectric relaxation measurements, electrical conductivity measurements, time-of-flight charge-carrier mobility measurements, transistor device fabrication and evaluation, ferroelectric measurements, electric-field poling techniques, laser Doppler vibrometry, electron microscopy and atomic force microscopy, wide-angle and small-angle X-ray scattering, viscoelastic measurements, and tensile testing.

We proposed a new design concept for creating “ion highways” by harnessing the molecular alignment of liquid crystals. This concept enabled the development of a flexible actuator that delivers rapid bending at up to 150 Hz under a low driving voltage of only 2 V (see Figure), and its unprecedented functionality was demonstrated in a ring-shaped haptic device. The technology paves the way toward haptics that allow users to experience distant objects as if they were being touched directly. It could enable realistic remote palpation in telemedicine and immersive virtual experiences, opening new possibilities for richer and more engaging human–machine interactions.