Searching for low friction conditions for moving a microscopic machine is an indispensable requirement for solving the energy saving problem. In order to approach this problem from the viewpoint of nanotechnology, nanoscale friction of the carbon interface formed by graphene and fullerenes is studied by using frictional force microscopy measurement and molecular mechanics simulation. The effects of the loading force, scanning direction, molecular orientation angle, and intercalated fullerene species on nano-scale friction appeared at fullerene/graphene interface (fullerene molecular bearings) and graphene/graphene interface will be discussed. For example, utilization of the loading force for C₆₀ molecular bearing is expected to lead to the development of the device to control the ON-OFF of the superlubric state. The anisotropy of nano-scale friction is explained based on the theory of superlubricity. The friction force is maximized for the commensurate contact of the honeycomb lattice at the interface, although the friction force rapidly decreases due to the increase of the lattice mismatch.

Injection needle used in life science can be applied to produce micrometer-sized ion beams. The needle is called tapered glass capillary optics and plays an important role in MeV-energy ion irradiation which is difficult with samples in liquid solution due to the ions’ short range. This technique realizes MeV-ion irradiation in liquid or in atmosphere for sample analysis and modification. To understand the ion transmission characteristics, the difference between keV and MeV ion cases is shown by introducing peculiar keV ion features, such as the focusing and the guiding effects as well as a delayed transmission phenomenon. Then the latest application experiments with MeV ion microbeams by the glass capillaries are reported.

For changing and directing cell fate, various external stimuli have been used. Plasma, the forth state of matter, has become available for those applications by recent technological advancement. In addition to selected cell killing and promotion of cell proliferation, plasma can be used to affect cell differentiation. To elucidate how the plasma affects cell fate, a microdevice referred to as Plasma-on-Chip was developed. By taking advantage of micro air-liquid interface formed in the microdevice, cells in liquid medium can be located in the vicinity of gaseous plasma. The microdevice achieved direct plasma exposure of cultured cells for changing and directing cell fate. Here, results and future prospects of studies utilizing the Plasma-on-Chip are described.

In recent years, basic research has been conducted to understand the biological effects of radiation at the atomic level toward advancing particle beam cancer treatment. Here we show some recent results on the basic process of biomolecular damage in liquid water caused by ion beams. A liquid molecular beam or microdroplet was used to prepare a biomolecular solution target in a vacuum. Secondary ion mass spectrometry was used to measure the damage to biomolecules by an ion beam. Through the experiment and simulation, we studied the energy range of secondary electrons involved in damaging biomolecules in liquid water caused by ion beams. The damage process that occurred near the ion track is described.

It is mandatory to survey the output performance of photovoltaic (PV) modules to operate a PV system, appropriately. This article introduces the outdoor electroluminescence (EL) method. Synchronized operation of image-sensor and injection current involving an appropriate bandpass optical filter allows us to obtain a clear EL image even in a high light intensity environment. The developed system also gives us an accurate estimation of the open-circuit voltage from each solar cell using the EL image.

Tandem solar cells composed of perovskite and hetero-junction crystalline silicon solar cells have gained global attention as next generation solar cells toward the carbon neutrality by 2050, and their conversion efficiencies are approaching 30 %. In this article, we show the latest results of the R&D activities for Kaneka’s 2-terminal tandem solar cells which have the conversion efficiency of nearly 29 % and discuss the light confinement technologies for tandem solar cells based on the optical simulations. In addition, we also introduce the 3-terminal tandem solar cells which have a potential to combine the state-of-art perovskite solar cells and Kaneka’s world champion back-contact type hetero-junction crystalline silicon solar cells.

Photoelectron spectroscopy is an experimental technique to directly observe the electronic structure of materials. In particular, Hard X-ray Photoelectron Spectroscopy (HAXPES) allows chemical states analysis of buried layers in electronic devices in a non-destructive manner. Laboratory-based HAXPES measurements have been achieved due to the latest developments in light sources and photoelectron analysers. In this review, we introduce the basic principles of photoelectron spectroscopy, as well as measurements with a laboratory-based HAXPES system equipped with a Ga source, and method to analyze depth profile using data science.