1. Synthesis of nanomaterials through energy-saving self-organization processes
It is theoretically predicted that arrays of inorganic nanoparticles (NPs) will exhibit functions that go beyond conventional principles. Self-assembly is an attracting approach for obtaining free-standing NP arrays in a large scale through energy-saving processes. We established techniques in which isotropic NPs self-assemble into 1D chain, 2D ring, and 3D vesicles in aqueous dispersions. Interplay between amphiphilic polymers and NPs is the key to these processes.
We are trying to elucidate the mechanism of these phenomena and applying the nano-objects as advanced functional materials.
2. Application of self-assembled protein nanofibers in the fields of energy & biomaterials
We have developed artificial proteins that are inspired from elastin, an extracellular matrix protein that provide biological tissues with elasticity. The elastin-like proteins attract attention as scaffolds for regenerative medicine and as materials for small-diameter vascular grafts.
We are also trying to add electron/ion transport functions to the well-defined nanofibers of the elastin-like proteins, aiming to develop flexible conductive materials and create interfaces between living body and machines.
3. Construction of wearable & implantable energy-harvesting devices
We are constructing triboelectric nanogenerators that convert mechanical energy into electrical energy. The developments of wearable and implantable nanogenerators are our main targets by using biodegradable polymers as dielectric layers.
4. Self-assembly of polymers in ionic liquids
Polymers consisting of different types of monomers (i.e., copolymers) are known to self-assemble in solutions. We study the self-assembly behavior in “ionic liquids”. Because ionic liquids show negligibly small vaper pressure; thus, we can perform transmission electron microscopy (TEM) in solution to observe the self-assembly structure in motion. By using not only the liquid-phase TEM, but also small-angle X-ray scattering (SAXS) and rheology measurements, we study the structure and dynamics of many kinds of polymer self-assemblies in ionic liquids. We also explore the possibility that the polymer/ionic liquid systems may be applied to electronic devices.