T. Hayashi

For assisting human motion, assistive devices working as muscles would be useful. A robot suit HAL (hybrid assistive limb) has been developed as an assistive device for lower limbs. Human can appropriately produce muscle contraction torque and control joint viscoelasticity by muscle effort such as co-contraction. Thus, to implement functions equivalent to human muscles using HAL, it is necessary to control viscoelasticity of HAL as well as to produce torque in accordance with operator's intentio

We studied the adsorption state of dimethyl disulfide and methylthiolate on the Au(111) surface by means of the density functional theory (DFT) within a generalized gradient approximation and experimental high-resolution electron energy loss spectroscopy (HREELS) techniques. It turns out that the methylthiolate adsorption is more stable than the dimethyl disulfide adsorption and that the most stable adsorption site for the methylthiolate is the bridge site slightly off-centered towards the fcc-h

Adhesion force analysis using atomic force microscopy clearly revealed for the first time the mechanism underlying the specific binding between a titanium surface and ferritin possessing the sequence of Ti-binding peptide in its N-terminal domain. Our results proved that the specific binding is due to double electrostatic bonds between charged residue and surface groups of the substrate. Furthermore, it is also demonstrated that the accretion of surfactant reduces nonspecific interactions, drama

The mechanism underlying the bioinertness of the self-assembled monolayers of oligo(ethylene glycol)-terminated alkanethiol (OEG-SAM) was investigated with protein adsorption experiments, platelet adhesion tests, and surface force measurements with an atomic force microscope (AFM). In this work, we performed systematic analysis with SAMs having various terminal groups (-OEG, -OH, -COOH, -NH(2), and -CH(3)). The results of the protein adsorption experiment by the quartz crystal microbalance (QCM)

For the first time, we report high-resolution electron energy loss spectroscopy (HREELS) studies on fluorinated carbon nanotubes and nanofibers of various diameters. In addition, we have carried out high-resolution transmission electron microscope studies on the material, as well as HREELS elemental line scans, and elemental mappings. From the experimental EEL near edge structure of the F−K edge, we observed that F establishes two different types of bonds with C: covalent and ionic. From the ele

We attempt to predict the water contact angle (WCA) of self-assembled monolayers (SAMs) and protein adsorption on the SAMs from the chemical structures of molecules constituting the SAMs using machine learning with an artificial neural network (ANN) model. After training the ANN with data of 145 SAMs, the ANN became capable of predicting the WCA and protein adsorption accurately. The analysis of the trained ANN quantitatively revealed the importance of each structural parameter for the WCA and p

The hydration forces between structureless model walls were calculated using the grand canonical Monte Carlo technique. Several wall–water interaction potentials were tried, including both orientation independent and strongly directional potentials which reflected the preference of water for tetrahedral hydrogen bonding coordination. Primary attention was given to large wall-to-wall separations (4 nm and more), where the oscillations of the hydration force due to layering effects decayed. The hy

A common rail injection system for diesel engines has a potential to realize low emission and low fuel consumption diesel combustion. The core technology of this system is accumulated on spray characteristics such as mean droplet diameter, spray cone angle and tip penetration. And these characteristics are greatly influenced by internal flow in a diesel nozzle. In order to clarify the internal flow phenomenon such as cavitation, a real-size transparent nozzle had been developed, which can realiz

The interactions of ferritins fused with a Ti-recognizing peptide (RKLPDA) and their mutants with titanium oxide substrates were explored with an atomic force microscope (AFM). The amino acid sequence of the peptide was systematically modified to elucidate the role of each amino acid residue in the specific interaction. Force measurements revealed a clear correlation among the sequences in the N-terminal domain of ferritin, surface potentials, and long-range electrostatic interactions. Measureme