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9. Industry, Innovation and Infrastructure: 101
- 1. No Poverty
- 2. Zero Hunger
- 3. Good Health and Well-being
- 4. Quality Education
- 5. Gender Equality
- 6. Clean Water and Sanitation
- 7. Affordable and Clean Energy
- 8. Decent Work and Economic Growth
- 9. Industry, Innovation and Infrastructure
- 10. Reduced Inequality
- 11. Sustainable Cities and Communities
- 12. Responsible Consumption and Production
- 13. Climate Action
- 14. Life Below Water
- 15. Life on Land
- 16. Peace and Justice Strong Institutions
- 17. Partnerships to achieve the Goal
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View Detail-
Search for Novel Spintronic Devices and Theoretical Study of the Energy Spectrum of Low-dimensional Electron Gas
Toward power-saving devices
We use condensed matter theory to study materials and structures called topological insulators and skyrmions of which the topology dominates the phenomena. At the same time, we are studying to propose and realize novel spin devices using these topological insulators and skyrmions in the process.
Research
We are proposing spin devices that exceed the current mainstream CMOS devices in terms of performance and power, and are analyzing their performance using condensed matter theory. The main objective of this research is to create power-saving devices that provide superior performance to CMOS devices. To calculate the performance of novel spin devices, quantum field theory and relativity are used to calculate the spin conductivity and other properties. Currently, we are studying topological insulators and skyrmions. Topological insulators are bulk insulators, but spontaneous spin currents flow only on their surfaces. If successfully applied to devices, topological insulators make it possible to fabricate ultra-low power devices because the topological insulator itself is non-dissipative. Skyrmions are also a peculiar vortex generated in magnetic materials, and are expected to play the role of a switch by driving a current.
Kenji Kondo Associate Professor -
Security Certification Technology for Quantum Key Distribution Devices
Experimental certification of ultimate cryptographic security
Using quantum key distribution, we can share cryptographic keys via optical communication while maintaining a high level of secrecy, no matter how the technology advances in the future. Through our research, we offer technologies to experimentally guarantee the security of quantum cryptography using an actual device to realize its practical application.
Research
The quantum key distribution technology has passed the proof‐of‐principle phase, and research is now under way with an eye on its practical application. Since this is a technology to realize the ultimate confidential communication, field tests and other researches on it are conducted worldwide. In our laboratory, we are examining both theoretical and implementation-related aspects on quantum key distribution. In the real world, things do not always go according to the theory, and experimental results sometimes differ from those expected in theory. Our goal is to examine these discrepancies and quantitatively guarantee the security of cryptographic keys produced on real devices. To this end, we are conducting research to fill the gap between the theoretical studies and the actual device development. We believe that this research will open the way to measure and evaluate the behaviors of the actual quantum devices, and finally to realize practical quantum systems, which will contribute to future quantum networks.
Akihisa Tomita Professor -
Semiconductor Precision Processing Technology
Low-damage and controllable semiconductor etching technology using electrochemical reactions
A semiconductor etching technique using electrochemical reactions was developed to reduce damage and achieve precise processing control in the depth direction compared with conventional methods, and was applied to the gate recess processing of AlGaN/GaN heterostructure transistors to realize normally-off transistors.
Research
The etching process of semiconductor surfaces is one of the essential steps in the fabrication of semiconductor devices such as transistors. In this laboratory, we have developed an etching method that is superior to conventional dry etching methods in terms of both depth control and damage suppression, by utilizing electrochemical oxidation and dissolution reactions on semiconductor surfaces. As a result of applying the method to AlGaN/GaN heterostructures, which are considered to be promising power transistor materials, it was revealed that the etching process can be self-stopped at the desired processing depth by optimizing the electrochemical conditions, thus eliminating the need for an etching stop layer, which had been essential in prior technologies, and enabling precise control of the transistor threshold in a simpler way. In addition, the etched surface by this method has less processing damage than the dry-etched surface, and is expected to be a promising method for improving transistor performance.
Taketomo Sato Associate Professor -
Simultaneous Observation of Electrical Properties and Structural Changes Using an Electron Microscope
The relationships between electrical properties and structural changes can be evaluated and validated
An electronic device fragment is placed in the electron microscope, and a movable probe electrode is applied to it, enabling observation by the electron microscope while evaluating its electrical characteristics. A MOSFET is connected to the sample side electrode to suppress excessive current. It allows evaluation of the correlation between electrical characteristics and structural changes and is useful to investigate the cause of failures.
Research
Our in-situ electron microscopy system is capable of three-terminal device measurements using two movable probes and a fixed sample holder as electrodes. A MOS transistor is inserted in the sample holder to limit the excess current flow due to stray capacitance.
Microelectronic devices that are almost ready for practical application include devices such as phase-change memory and resistance change memory that can predict structural changes accompanying resistance changes. It is difficult to confirm the mechanism of resistance changes in microdevices due to their high operating speed and nanoscale structure, but this system enables the evaluation of such a mechanism and helps to efficiently investigate the cause of the defective operation and ensure its reliability. By using this system, we can also effectively confirm the operating functions and evaluate the causes of defects in nanostructured functional devices, such as nanomachines and nanostructured secondary batteries, which are expected to be further developed in the future. -
Soft Error Testing of Telecommunication Equipment Using a Compact Electron Accelerator Neutron Source
Preventing malfunctioning of telecommunication devices caused by cosmic rays
As the semiconductor devices of equipment that support telecommunication networks are becoming more intensively integrated, there is concern that the probability of soft errors caused by cosmic-ray neutrons will increase. To address this problem, we are conducting soft error tests of telecommunication devices using a compact accelerator-driven neutron source at Hokkaido University.
Research
As telecommunication devices increase in capacity and become more sophisticated, semiconductor devices are becoming more and more integrated. However, there is concern that cosmic ray neutrons may cause an increase in soft errors, such as bit information upset and operation confusion. Therefore, in collaboration with NTT, we have reproduced soft errors using a compact electron accelerator-driven neutron source to create a place to develop countermeasure technologies in advance. This enables the advance prediction of the failure rate in the natural environment, the detection of errors and verification of operational measures, which will lead to improved reliability of the equipment.
The feature of this technology is the use of a compact accelerator-driven neutron source. In the past, large-scale accelerator-based neutron sources were required, and it was difficult to secure sufficient test time and experimental space. However, through our research, we have demonstrated that it is possible to conduct sufficient tests even in a facility with a neutron intensity of several million times that in nature.Hirotaka Sato Associate Professor -
Sonoplasma Generator
A method to generate acoustic cavitation in a fixed location with high efficiency
Upon the collapse of acoustic cavitation driven by ultrasonic waves in water, the bubble becomes hot and pressure inside increases, turning to plasma (sonoplasma). We have found a way to generate acoustic cavitation in a fixed location with high efficiency, and are working to develop it as a plasma application technology.
Research
Plasmas generated in liquid are of great interest in the fields of nanotechnology, environmental engineering and medical engineering, but the need for high voltage to generate the plasma can be an obstacle. Meanwhile, in the field of ultrasonic engineering, it is known that the interior of a bubble becomes plasma at the same time as the collapse of acoustic cavitation. Using a very simple method of inserting a perforated metal plate into a liquid where ultrasonic waves are applied, we have succeeded in localizing and efficiently generating acoustic cavitation, which is difficult to fix in position. This has been valued as a unique method of generating plasma in liquid without using high voltage. Currently, we are working to clarify the mechanism of this method and to prepare guidelines for the design of a large-scale device. In the future, we hope to develop various new plasma application technologies.
Koichi Sasaki Professor -
Sonoporation: Development of a New Drug Delivery Method Using Ultrasound and Microbubbles
Realization of tissue targeting capability at the cellular level
We were the first in the world to show that, by irradiating cells with pulsed ultrasound while microbubbles of several microns in diameter are attached to the cells, we can temporarily increase the cell membrane permeability. We are now promoting research aimed at realizing drug and gene delivery to living organisms.
Research
○ Acoustic perforation (sonoporation) using microbubbles and pulsed ultrasound: Pulsed ultrasound irradiation of microbubbles in contact with the cell membrane enables temporary perforation only at the attachment site (Fig. 1). We have realized a method to deliver drugs or genes into any desired position in the target cell by adding drugs or genes to the microbubbles and controlling the attachment site with optical tweezers.
○ Succeeding with therapeutic site identification and drug delivery by using microbubbles and an ultrasound system: A microbubble, which has the target function of adhering only to the cells to be treated, is injected into a vein. To identify the therapeutic site, the tissue where the bubbles have accumulated is detected using an ultrasound contrast method. Pulsed ultrasound waves are then generated to break the bubbles, allowing temporary perforation of the cell membrane and drug delivery (Fig. 2). By adding drugs or genes to the bubbles, highly efficient drug delivery only to the target cells can be realized.Nobuki Kudo Associate Professor -
Spatio-temporal Control of Laguerre-Gaussian Light
Information multiplexing using the spatial phase of light
In this study, we have developed a fundamental technology for information multiplexing using Laguerre-Gaussian (LG) light, which has a characteristic spatial phase. By focusing on the spatial phase, which has not been actively used in conventional optical information processing, we aim to increase the information capacity.
Research
Optical information processing, transmission, recording and reproduction are performed using the intensity, polarization and spatially uniform phase of laser light. The transmission capacity can be increased through multiplexing using different frequencies. In contrast, the spatial characteristics of light form an unexplored area that has not been actively utilized until now. Based on this background, information multiplexing using Laguerre-Gaussian (LG) light and quantum information processing using the orbital angular momentum (topological charge) that characterizes LG light have been attracting attention as a step to overcome the limitation of information processing capacity. In this study, we have utilized material interaction and realized the mode control of LG light and the conversion and conservation of orbital angular momentum using short-pulsed light, as well as space-division multiplexing fiber transmission.
Yasunori Toda Professor -
Stabilization of Nanoparticles Using Cyclic Poly(ethylene Glycol)
A novel stabilization method relying on the “topology” of polymers
In this research, we developed a novel dispersion stabilization method for metal nanoparticles using cyclic poly(ethylene glycol). The research group has found that molecular aggregates consisting of cyclic polymers have excellent stability. By applying this phenomenon, the dispersion stability of nanoparticles can be enhanced.
Research
A large number of nanoparticle-based drugs are currently investigated, including drug delivery system (DDS) carriers, many of their surface is covered with biocompatible poly(ethylene glycol) (PEG). In this regard, we have found that gold nanoparticles (AuNPs) modified with cyclic PEG exhibit high dispersion stability at high salt concentrations. In other words, AuNPs treated with cyclic PEG with a molecular weight of 4000 retained their dispersion stability for one week or longer in a 180 mM NaCl solution, which is a higher concentration than physiological conditions, whereas AuNPs treated with linear PEG of the same molecular weight started aggregating and precipitating within 3 hours in a solution of only 45 mM NaCl. This novel method using cyclic PEG can be applied to a variety of nanoparticle-based drugs including contrast agents and magnetic nanoparticles.
Takuya Yamamoto Associate Professor -
Steam/Water Mixture Spray Cleaning Method with an Ultra-low Impact on the Environment
An ultraprecise and safe cleaning method making use of the physical action of steam and water and no chemicals.
We have developed an innovative cleaning method using a completely new vapor-water multiphase spray method, whereby water and steam are mixed and sprayed at high speed from a nozzle. This method is especially notable for not using any chemicals and minimizing the burden on the environment.
We have confirmed that the specified performance can be achieved with ultra-precision cleaning during semiconductor manufacturing processes, etc.Research
Based on our previous research results, we have discovered that when a droplet hits a solid surface in a condensable gas (not air), splashing is suppressed and a thin liquid film (lamella) spreads on the solid surface at high speed. Since the high-speed lamellae may generate a strong fluid shear force, it seemed possible to use a mixed jet of steam and water to realize an environmentally friendly cleaning method.
Based on our previous research results, we have confirmed that this cleaning method, which uses only water and steam, can achieve the specified cleaning performance for ultra-precision cleaning required in the manufacturing processes of semiconductors, LEDs, and solar cells. This cleaning method is also safe both for the human body and the environment, because it uses only water and steam instead of detergents or other chemicals that are harmful to the human body.Masao Watanabe Professor -
Super-hierarchical Structure Imaging Through the Combined Use of Neutrons and X-rays
Non-destructive imaging of unknown information over a wide range of scales using multi-quantum beams
Pulsed neutron transmission spectroscopy imaging is attracting attention as a method of non-destructive visualization of information that cannot be seen with other microscopic methods, and when it is combined with other quantum beams such as X-rays, it is possible to visualize information that cannot be seen with images alone.
Research
Hokkaido University’s laboratory facilities, where small accelerators are used, have a history of nearly half a century, and are attracting worldwide attention as pioneering facilities. We mainly produce pulsed neutron beams, and the transmission spectra obtained using these beams enable us to map information on crystal structure, microstructure, internal stress and temperature on a two-dimensional real image as a distribution map of the entire sample. We also use X-ray CT which can measure the three-dimensional structure of the inside of an object, and analyze the combined results from neutrons and X-ray studies to synergistically understand the interior information of an object. In the figure, shown as synergistic imaging based on information from neutrons and X-rays, information on elements that cannot be individually obtained is mapped on the inside structure shown on the X-ray CT image. X-ray CT shows the presence of wires in an Al cylinder, but when neutron information is added, we can see that each wire is a different material.
Takashi Kamiyama Professor -
Superomniphobic Aluminum
Simple production of antifouling surfaces through a wet process
We have successfully fabricated a micro/nano-hierarchical surface morphology through chemical etching/anodization of aluminum sheets and meshes. By coating the surface with a fluoroalkyl monolayer, we have also succeeded in obtaining a surface that is not wetted by almost any liquids, including oil.
Research
It is expected that superomniphobic surfaces, which do not get wet with water or oil, will possess antifouling and self-cleaning properties. In this study, we have realized a superomniphobic surface that does not only repel water but also octane and other liquids with a surface tension as low as 20 mN m-1, by using a simple wet process for aluminum, which is a practical metal material. This process can also be applied to aluminum foil, which can be used as an antifouling surface in various places. It can also be used as a filter to separate oil and water by controlling its wettability using aluminum mesh.
Hiroki Habazaki Professor -
Synthesis of Fluorinated Aromatic Carboxylic Acids
Using electricity to make useful carboxylic acids from carbon dioxide
We have succeeded in regioselectively synthesizing a variety of fluorine-containing aromatic carboxylic acids, which are promising as new fluorine-containing building blocks, from readily available aromatic compounds containing several fluorine atoms and carbon dioxide, and achieved good yields by organic electrolysis.
Research
The introduction of fluorine atoms into organic compounds is very important in the fields of medicine, agrochemicals, and functional materials. There is a method of synthesizing fluorine-containing organic compounds by using fluorine-containing building blocks, but such compounds are still expensive and limited in quantity, and there is a high need for research and development. In this study, we succeeded in synthesizing fluorine-containing aromatic carboxylic acids with various functional groups from readily available fluorine-containing aromatic compounds and carbon dioxide, and achieved good yields using the organic electrolysis method. The fluorine-containing aromatic carboxylic acids synthesized in this study include a variety of new compounds that are difficult to synthesize by conventional methods, and are expected to be used as promising new fluorine-containing building blocks for the synthesis of pharmaceuticals, agrochemicals, and highly functional materials.
Hisanori Senboku Associate Professor -
Technology to Analyze Glycan Patterns Directly from Glycoproteins
The world's first selective ionization technology for glycans that does not require pretreatment
(This is a technology for which Hokkaido University is the sole applicant and sole inventor.)We have discovered the world's first mass spectrometry technique for selective ionization of glycans in complex macromolecules and mixtures such as glycoproteins and body fluids by the MALDI method. We have also demonstrated that this technique can be used for the direct analysis of glycans in complex mixtures such as egg white and body fluids.
Research
Glycan patterns on glycoproteins are important biomarkers because they are factors that determine the disposition of protein in the body. Until now, glycan pattern analysis has required complicated operations such as cutting, chemical modification, and purification of glycans. Mass spectrometry is an ultra-sensitive and high-resolution analytical technique that can directly ionize trace amounts of biomolecules. However, there has not been a method to selectively ionize glycoconjugates such as glycoproteins and glycans in complex macromolecules and mixtures such as body fluids, which requires the complicated pretreatment described above. We have achieved the world's first simultaneous selective cleavage and selective ionization of glycoconjugate glycans, and succeeded in the direct analysis of glycan patterns on glycoproteins. We have also demonstrated that this technique can be used to directly analyze glycan patterns in complex mixtures such as egg white.
Hiroshi Hinou Professor ProfessorPh.D. -
Technology to Create Unique Glycan Derivative Libraries × Microarray Analysis System That Can Be Used Anywhere
Original library using automated glycan synthesis technology × Microarray technology supporting on-site medical care and research
Glycan-related interactions are important targets of infectious diseases and cancer diagnosis. We have developed a microarray system that can be used anywhere to utilize the libraries of glycans, glycoconjugates, glycan-related inhibitors, and their derivatives that have been constructed and accumulated in the process of developing automated glycan synthesis technology.
Research
Microarray technology is a technology that enables simultaneous comparative analysis of the interaction between a large number of compound libraries with well-defined structures and sequences and sample components. We also have the most advanced technology to design and produce our own carbohydrate compound libraries as molecules for microarray analysis based on our automated carbohydrate synthesis technology. The interaction information possessed by carbohydrates is widely used as biomarkers for in vitro diagnostics, such as blood types, serotypes such as O157, and cancer diagnostic markers (CAxx). In addition, we have succeeded in developing an independently powered mobile analyzer that can be used for online diagnosis, such as analysis of infection patterns associated with mutations in infectious diseases and detailed analysis of vaccine effects, by performing specimen collection and microarray analysis on the spot using a smartphone as a terminal.
Hiroshi Hinou Professor ProfessorPh.D. -
Time-resolved Two-dimensional Surface Acoustic Wave Imaging
Excitation and detection of arbitrary frequency response by optical pulse train with fixed period
This technique visualizes the propagation of surface acoustic waves up to the GHz frequency range as a time-resolved two-dimensional image. Conventional methods involve the problem of low frequency resolution, but this method can excite and detect acoustic waves of any frequency.
Research
Visualization of acoustic wave propagation is extremely useful in the evaluation of physical properties and the design, fabrication and evaluation of functional devices using acoustic waves. For this purpose, we excite surface acoustic waves by irradiating the sample with an ultrashort optical pulse of subpicosecond duration (pump light), and observe their propagation with delayed optical pulse (probe light). Time-resolved two-dimensional images of the acoustic waves are obtained by scanning the delay time and the irradiation position of the probe light. The time resolution is in picoseconds, the spatial resolution is 1μm, and the frequency range is in GHz. Since this method uses a periodic optical pulse train, it was previously only possible to excite and detect acoustic waves at integer multiples of the repetition rate. However, with the newly developed technique, we have realized the excitation and detection of acoustic waves of any frequency. By developing this technique, we have also achieved image vibrations that are completely asynchronous to the repetition frequency of the optical pulse, thereby expanding the range of applications.
Osamu Matsuda Professor -
Tumor Angiogenesis Inhibitor Screening System
A cell-based screening assay system for the development of tumor angiogenesis inhibitors
We aim to realize cell-based screening using tumor vascular endothelial cells, and contribute to the development of next-generation angiogenesis inhibitor therapies by overcoming problems of existing angiogenesis inhibitors (side effects, lack of companion diagnostics).
Research
Thanks to the development of molecular targeted therapies, antiangiogenic agents are now widely used. However, there are problems such as the lack of companion diagnostics to predict therapeutic effects and side effects due to injury to normal blood vessels.
We have successfully isolated and cultured human tumor vascular endothelial cells and have identified specific markers that they express. Tumor vascular endothelial cells expressing these markers are valuable materials for cell-based screening of novel drugs and compounds, and help us identify new therapeutic targets and drugs that cannot be discovered by studies using conventional tumor cell lines or clinical tumor tissue fragments. Markers expressed by these tumor vascular endothelial cells can also be used as companion diagnostics. This will contribute to the realization of personalized treatment by selecting the target cases as well as the timing and duration of administration with angiogenesis inhibitors.Kyoko Hida Professor -
Ultimate Behavior Analysis of Seismically-Isolated Structures
To prepare for a mega earthquake
Our laboratory is developing advanced analysis techniques for seismic isolation systems, and can predict the ultimate behavior of seismically-isolated buildings in the event of a mega earthquake, and propose various countermeasures to prepare for a mega earthquake.
Research
In a seismically-isolated building, the seismic isolators deform softly during an earthquake, greatly reduce response acceleration in the superstructure and improve the seismic safety. On the other hand, ultimate events such as collisions with retaining walls and buckling or rupture of the seismic isolation bearings may occur for the ground motions exceeding design level caused by a mega earthquake such as the Nankai Trough Mega Earthquake. By using analysis technologies to precisely predict the ultimate behavior of seismically-isolated buildings, it is possible to foresee the occurrence of ultimate events and to consider countermeasures to suppress their occurrence.
Masaru Kikuchi Professor -
Ultra-rapid Deposition of Photocatalytic Crystalline Titanium Dioxide Thin Films
Ultra-rapid electrochemical deposition technology that does not require high temperature heat treatment
Crystalline titanium dioxide is a practically important oxide as a photocatalyst. We have developed a technology to form crystalline titanium dioxide thin films, which generally require heat treatment at high temperatures, on various metal substrates within only a few seconds using an electrochemical deposition method in aqueous solution.
Research
We have succeeded in obtaining titanium dioxide thin film on a practical metal substrate such as Cu, Al, Zn and Fe by electrolysis from an aqueous solution containing TiF62- within only a few seconds. The obtained titanium dioxide thin film is anatase crystalline and shows photocatalytic activity without heat treatment. The obtained titanium dioxide thin film is anatase crystalline and shows photocatalytic activity without heat treatment. We have confirmed that it has excellent properties such as decomposition of organic contaminants on the surface by UV irradiation and superhydrophilicity. Since the titanium dioxide film is doped with substrate elements, the development of new functions such as visible light responsiveness can be expected. It can also be deposited on a transparent conductive substrate.
Hiroki Habazaki Professor -
Vibration Measurement Technology Using a Non-contact Laser Excitation System
Development of high-frequency vibration measurement and high-sensitivity damage detection technology
We have developed a technique to apply an ideal impulse excitation force using laser ablation generated on a structural surface by high-power pulsed laser irradiation. This technology enables non-contact, high-precision vibration measurement in the high-frequency range, which had previously been impossible.
Research
As in Fig. 1, which shows the principle of laser-induced excitation force generation, the laser-induced excitation force is caused by laser ablation. Figure 2 shows an example of the application of this technology, a vacuum environmental excitation measurement system for a membrane structure. This system consists of a YAG-pulsed laser, dielectric multilayer mirror, collecting lens, membrane structure, LDV and vacuum chamber. The membrane structure is fixed inside the vacuum chamber, allowing us to conduct the experiment by adjusting the air pressure inside the chamber from the atmospheric to the vacuum environment. Figure 3 shows the measured frequency response of the membrane. As shown in Fig. 3, with an increase in the vacuum level, the resonance frequency of the membrane becomes higher and at the same time the resonant response level increases. In this way, this technology enables the extraction of both mass effect and damping effect caused by the air on the membrane surface. We have conducted experiments to verify the effectiveness of this technology in a vacuum chamber, which assumes a space environment.
Itsuro Kajiwara Professor
