Research visibility
2.26FWVI
Research that reaches readers.
Field-Weighted Views Impact measures publication views adjusted for subject area, publication year and document type.
Source: SciVal; field-normalized views impact.
Tohoku University
Cavitation Interface Science
Using ultrasound and microwaves to activate solid–liquid–gas three-phase interfaces and synthesize functional materials more simply, at lower temperatures,and more sustainably.
Ultrasound
Microwave
Interface
Materials
Be the first into a new reaction field.
LATESTDirect synthesis of iron oxide nanoparticles from iron powder and water only — Tohoku University Press Release2026.09.01 ↗
Research concept
Design sustainability
from the reaction field.
We deliver localized, non-equilibrium energy generated by external fields to solid–liquid interfaces, enabling direct transformations and materials formation that are difficult to achieve under conventional thermal-equilibrium processing.
Design where, when, and how energy is delivered.
The goal is not simply to reduce total energy input. It is to design where, when, and how energy is delivered, and to activate only the interfaces that matter. This is our approach to sustainable processing.
Low temperature × Short time × Dispersant-free × Washing-free × High concentration
Specific reaction fields enable simpler pathways from raw materials to functional products.26Research papers2021–2026
19Corresponding author2021–2026
17/26Q1 journals
12/26Top 10% journals
Research impact · collaboration · mentoring
Beyond publications,the reach of research.
From interest in our research to industry collaboration and student achievements, these figures show work that a publication list alone cannot capture.
Industry collaboration
87industry collaboration activities
3casesSocial implementationResearch applied to practical challenges.
We work with companies on materials discovery, wet synthesis, conductive and bonding materials, and process design, translating research outcomes into real-world applications.
As of 1 September 2026. The 87 are collaborative research funding and related activities with private organizations as principal investigator, including joint research, academic guidance, MTAs and donations. Separately: 23 patent licensing and option agreements as principal investigator.
Mentoring & student achievements
63student conference awards
Passing discoveries to the next generation.
Students grow as researchers through conference presentations, first-author papers and recognition of their work.
Student conference awards, 2016–2025: sum of annual domestic and international conference awards (as of 1 September 2026).
FWVI measures views; it is different from FWCI, a citation impact metric.
Research pillars
Four research pillars
We treat external fields, interfaces, materials, and processing as one integrated system, linking fundamental phenomena to implementable materials manufacturing.
01
Ultrasound &
Cavitation
Control solid surfaces and particle formation through shock waves, microjets, and localized reaction fields generated by bubble collapse.
- Sonochemistry
- Bubble dynamics
02
Microwave &
Specific Fields
Use selective heating and electromagnetic-field responses to design reaction pathways and material structures beyond thermal-equilibrium constraints.
- Selective heating
- Nonequilibrium
03
Functional
Nanomaterials
Direct and simplified fabrication of metal, oxide, and composite nanomaterials, functionally graded materials (FGMs), and nanosolder.
- Metal / Oxide
- Nanosolder
04
Sustainable
Processing
Reduce reagents, process steps, and liquid waste while advancing high-concentration synthesis, high recovery, and upcycling.
- Reagent-free
- Upcycling
Research infrastructure
From ultrasonic and microwave synthesis systems to materials characterization instruments.
Featured research · 2026
From solid feedstocks to diverse functional materials.
Iron oxide nanoparticles from iron powder and water only.
Acoustic cavitation activates the solid iron–water interface, directly converting metallic iron into magnetic iron oxide nanoparticles without iron salts or precipitating agents.
Read the paper ↗
Ag / GLASS · JMRT 44Ultrasonic control of microstructure in Ag/glass conductive composites3270–3276 · 2026 ↗
Ag / Si · USS 131Ag/Si nanocomposites via selective Ag nanoparticle nucleation at the interfaceArticle 107942 · 2026 ↗
Ag / SILICONE · USS 120Functionally graded Ag/silicone rubber compositesArticle 107496 · 2025 ↗
CuO → Cu · Research series
From high-concentration synthesis to conductive films.
Three studies using copper oxide as the starting material
CuO → Cu · CLEANER ENG. TECH. 29High-concentration, dispersant-free synthesis of Cu nanoparticles101108 · 2025 ↗
CuO → Cu · JCS-JAPAN 134Cu particles via solid–liquid reduction with fewer processing steps103–109 · 2026 ↗
CuO → Cu · MATER. CHEM. PHYS. 364Washing-free Cu nanoparticles and low-temperature sintering132866 · 2026 ↗
Liquid Ga alloys · Sonochemistry
From liquid metals to oxides and composite particles.
Acoustic emulsification and interfacial oxidation in Ga-based materials
Materials portfolio
One reaction-field concept, an expanding materials portfolio.
Using ultrasound and microwaves, we extend low-temperature direct conversion and simplified processing to carbon materials, oxides, alloys, porous materials, and conductive films.
Graphene · Nanocarbon
At low temperature and without reagents,
from graphite to graphene.
A sustainable process that directly exfoliates layered carbon using ultrasound and microwaves, avoiding the graphene-oxide route that requires strong oxidants.
Research overview ↗Silica nanoparticles
At room temperature, from metallic silicon
to high-purity silica nanoparticles.
Using metallic Si rather than expensive alkoxide precursors, spherical silica nanoparticles are synthesized directly at room temperature under ultrasonic irradiation.
Paper ↗Gallium oxide
Without relying on high-temperature calcination,
from Ga to γ-Ga₂O₃ at room temperature.
A non-equilibrium materials transformation in which ultrasonic cavitation of liquid gallium forms gallium oxide nanoparticles at room temperature.
Paper ↗Sonochemical alloying
Replacing alloying above 1000 °C
with Au–Ag alloying at room temperature.
A new alloying concept that uses sonochemical reduction of noble-metal oxides to form Au–Ag alloys at room temperature, instead of conventional high-temperature melting.
Research topic ↗Aerogel / Xerogel
Accelerating time-consuming porous-material formation
to less than one-fifth of the processing time with ultrasound.
Ultrasonic irradiation of semi-solid silica gels accelerates aging and hydrophobization, greatly shortening the time required to form low-density porous silica.
Paper ↗Silver nanowire · Flexible electronics
Connecting silver-nanowire synthesis and film formation
directly to flexible transparent conductive films.
Needle-like organic precursors are synthesized ultrasonically, then coated and reduced to form silver nanowire films—integrating conventional “nanowire synthesis + film fabrication” into a simpler process sequence.
Research overview ↗Selected publications
Recent works
We are extending Cavitation Interface Science to oxides, metals, and conductive and bonding materials.
The left column indicates the online publication date.US= ultrasound,MW= microwave.CSP = Scopus CiteScore highest percentile (2025).
Reagent-free sonochemical synthesis of iron oxide nanoparticles from iron powder and water promoted by acoustic cavitationMadoka Yoshikawa, Hirotsugu Takizawa, Yamato Hayashi*
USUSS 133108028CSP: 99%
Ultrasound-assisted fabrication of microstructure-controlled Ag/glass conductive composites with relatively homogeneous Ag distributionsYamato Hayashi*, Madoka Yoshikawa, Kou Takizawa, Hirotsugu Takizawa
USJMRT 443270–3276CSP: 90%
Acetic-acid-assisted washing-free synthesis of Cu nanoparticles from CuO for low-temperature sintering of conductive filmsYamato Hayashi*, Takaharu Nakajima, Yoshihiro Sekiguchi, Hirotsugu Takizawa
MWMCP 364132866CSP: 89%
Sonochemical cavitation–driven interfacial-selective nucleation of silver nanoparticles via silver carboxylate precursors for Ag/Si nanocompositesHaruto Tsuchiya, Haruki Kawamoto, Hirotsugu Takizawa, Minoru Ueshima, Yamato Hayashi*
USUSS 131107942CSP: 99%
Synthesis of Cu fine particles via a solid–liquid reduction method using copper oxideYuto Ishida, Yamato Hayashi*, Hirotsugu Takizawa, Minoru Ueshima
MWJCS-JAPAN134, 103–109CSP: 37%
Patents & technology transfer
Turning research outcomes into usable technology.
Three cases of social implementation born from industry collaboration, together with 12 selected examples from the public intellectual-property portfolio.
Intellectual property portfolio · 12 examples
Selected intellectual property supporting social implementation.
Layered nanosheets
Method for producing nanosheets of layered materials
Exfoliation and nanosheet production for layered materials such as graphite and MoS₂.
Amorphous nanoparticles
Amorphous nanoparticles and their dispersions
Ultrasonic treatment of alloy powders to obtain amorphous nanoparticles and dispersions at low temperature, including Sn–Bi alloy systems.
Ultrasonic processing
Ultrasonic processing apparatus and method
Process equipment combining a liquid flow path with ultrasonic treatment for integration into materials manufacturing.
Particle production
Method and apparatus for producing metal particles
A production method and apparatus for forming fine metal particles in liquid media, including solder alloys.
Copper particles
Copper fine particles, dispersions, and production method
Materials-processing technology for copper fine particles and their dispersions, relevant to conductive materials.
Nanosolder
Metal-nanoparticle dispersion for solder paste
Alloy-derived metal-nanoparticle dispersions for use in solder-paste production.
Porous metal wire
Porous metal wire and films containing it
Materials and film-fabrication technology covering porous metal wires, films containing them, and their production.
Ceramic / carbon
Oxide ceramic–carbon composite
Microwave-assisted production of Li₄Ti₅O₁₂–carbon composites; a technology-transfer summary is also available from Tohoku Techno Arch.
Precious metals
Method for producing precious-metal nanomaterials
Ultrasonic dispersion of precious-metal oxides combined with heating, including microwave heating, to produce fine particles and nanostructures for potential catalytic use.
Gold particles
Method for producing fine gold particles
Ultrasonic reduction of gold oxide to form fine gold particles, with potential use in conductive gold pastes as an alternative to gold plating.
Gallium oxide
Method for producing gallium oxide
Ultrasonic treatment of a liquid-gallium-containing precursor to form particles containing γ-Ga₂O₃ at low temperature.
Metal / oxide particles
Method for producing metal and metal-oxide fine particles
Oxidation and liquid-phase reduction to refine source materials into particles, including metal-containing pastes and metal or metal-oxide films.
For companies exploring applications or joint research
Tell us which technology, material, or process interests you. Research and joint-development questions and intellectual-property licensing inquiries have separate contact points.
The total of 20 refers to the industrial property rights listed in the Tohoku University researcher profile (checked 18 September 2026). The 12 items above are selected examples. Publication and grant information reflects the cited records; current legal status and licensing availability should be checked for each case.
Recognition & activities
Connecting research with society and the next generation.
Award
Japan Society of Sonochemistry Paper Award
Awarded for sustainable sonoprocessing research on room-temperature oxidation of liquid metals and core–shell particle formation.
Book chapter
Bonding Technologies and Materials for Semiconductor Devices
Book chapter on bonding technologies using nanomaterials. Technical Information Institute Co., Ltd., ISBN 978-4-86798-164-1.
International keynote
ISFM 2026 Keynote
Keynote presentation on sustainable materials processing enabled by Specific Reaction Fields.
Profile
Turning transient interfacial events
into materials processing.
Since 1998, my research has developed from ultrasound to nanoparticles (since 2001) and microwave processing (since 2003). I advance “Cavitation Interface Science,” which applies external fields to solid–liquid–gas three-phase interfaces to integrate control of reaction, nucleation, particle growth, and composite formation.
SonochemistryAcoustic cavitationMicrowave processingMetal nanoparticlesOxide materialsFGMNanosolderUpcycling
Collaboration / Contact
We welcome collaborative research and technical consultation on ultrasonic and microwave processing, metal and oxide nanomaterials, bonding materials, and upcycling.
yamato.hayashi.b6@tohoku.ac.jp
From the laboratory
to society.
Research outcomes have advanced through joint development with companies into products and practical technologies—connecting sustainable materials processing with real-world use.
Gallium-particle-dispersed winter sports wax
Jointly developed with GALLIUM Co., Ltd., this technology simultaneously synthesizes fine gallium particles and disperses them throughout wax without physical grinding. The shorter, energy-efficient manufacturing process has been adopted in six product lines.
Low-temperature, 200 °C heat-resistant nanosolder
Developed with Panasonic Holdings, NEDO, and university partners, the bonding material uses a solid–liquid reaction between low- and high-melting-point metals. It combines bonding at 200 °C in 10 minutes with 200 °C heat resistance after bonding.
Protectant-free water-based platinum nano dispersion
Building on results from the NEDO Industrial Technology Research Grant Program (Young Researcher Grant), this product was jointly developed with Shikoku Instrumentation Co., Ltd. The process disperses 3 nm primary platinum nanoparticles in a water-based medium without protective agents and eliminates washing and waste-treatment steps. It was commercialized through Kanto Chemical Co., Inc.