41 citations · 152 across the 20 of their papers we have counts for
21 papers
Apparent Breakdown of the Stress-Optic Rule in Rigid-Rod Suspensions: A Stress-Partitioning Interpretation
William Kai Alexander Worby, Yuto Yokoyama, Misa Kawaguchi +1
A fundamental problem in the field of anisotropic macromolecular materials concerns how the flow-induced orientational order connects microscopic structure to macroscopic rheologic…
Time-Resolved Stress Analysis of Tissue Simulants During Needle-Free Jet Injection
Kohei Yamagata, Prasad Sonar, Kazuhiro Terai +2
Needle-free jet injection generates transient internal stress fields that can influence tissue deformation, pain-related stimulation, and cellular-level mechanical responses. Howev…
Flow-history-dependent orientational relaxation in dilute polydisperse colloidal rod suspensions
Yuto Yokoyama, Vincenzo Calabrese, Fabian Hillebrand +3
Orientation and relaxation dynamics of rod-like colloids under flow govern the optical and mechanical properties of many emerging soft materials. In polydisperse suspensions, parti…
Penetration of impact-induced jets into skin-simulating materials
Kohei Yamagata, Yuto Yokoyama, Shoto Sekiguchi +3
This study compares the penetration characteristics of impact-induced jets with those of laser-induced jets, focusing on the underlying penetration mechanism rather than device per…
Interfacial dynamics induced by impacts across rigid and soft substrates
Ishin Kikuchi, Hiroya Watanabe, Yuto Yokoyama +2
We investigate impact-induced gas-liquid interfacial dynamics through experiments in which a liquid-filled container impacts substrates with elastic moduli from MPa to…
Extending flow birefringence analysis to combined extensional-shear flows via Jeffery-Hamel flow measurements
Miu Kobayashi, William Kai Alexander Worby, Misa Kawaguchi +3
This study investigates the relationship between phase retardation and strain rates in combined extensional-shear flows using the Jeffery-Hamel flow formalism, which yields an anal…
Reconstruction of three-dimensional fluid stress field via photoelasticity using physics-informed convolutional encoder-decoder
Daichi Igarashi, Shunsuke Kumagai, Yuto Yokoyama +3
Measuring stress fields in fluids and soft materials is crucial in various fields such as mechanical engineering, medicine, and bioengineering. However, conventional methods that c…
Flow birefringence measurement in a radial Hele-Shaw cell considering three-dimensional effects
Misa Kawaguchi, William Kai Alexander Worby, Yuto Yokoyama +3
Flow birefringence measurement is an emerging technique for visualizing stress fields in fluid flows. This study investigates flow birefringence in the steady radial Hele-Shaw flow…
Droplet impact on elastic substrates: force scaling crossover
Yuto Yokoyama, Hirokazu Maruoka, Yoshiyuki Tagawa
Droplet impacts are fundamental to fluid-structure interactions, shaping processes from erosion to bioprinting. While previous scaling laws have provided insights into droplet dyna…
Examination of flow birefringence induced by the shear components along the optical axis using a parallel-plate-type rheometer
William Kai Alexander Worby, Kento Nakamine, Yuto Yokoyama +2
In this study, the concept of rheo-optics is applied that explores the flow birefringence caused by stress components along the optical axis of the camera since it is often overloo…
Flow birefringence of cellulose nanocrystal suspensions in three-dimensional flow fields: revisiting the stress-optic law
Kento Nakamine, Yuto Yokoyama, William Kai Alexander Worby +2
This study systematically investigates the flow birefringence of cellulose nanocrystal (CNC) suspensions. The aim is to clarify the importance of the stress component along the cam…
Optimal standoff distance for a highly focused microjet penetrating a soft material
Daichi Igarashi, Kento Kimura, Nanami Endo +3
A needle-free injector using a highly focused microjet has the potential to minimize the invasiveness of drug delivery. In this study, the jet penetration depth in a soft material-…
High-speed photoelastic tomography for axisymmetric stress fields in a soft material: temporal evolution of all stress components
Yuto Yokoyama, Sayaka Ichihara, Yoshiyuki Tagawa
This study presents a novel approach for reconstructing all stress components of the dynamic axisymmetric fields of a soft material using photoelastic tomography (PT) and a high-sp…
The effects of cavitation position on the velocity of a laser-induced microjet extracted using explainable artificial intelligence
Daichi Igarashi, Jingzu Yee, Yuto Yokoyama +2
The control of the velocity of a high-speed laser-induced microjet is crucial in applications such as needle-free injection. Previous studies have indicated that the jet velocity i…
Measurement of flow birefringence induced by the shear components along the optical axis using a parallel-plate-type rheometer
William Kai Alexander Worby, Kento Nakamine, Yuto Yokoyama +2
The present study investigated the flow birefringence induced by shear components along a camera's optical axis, which has been neglected in conventional theories of photoelastic m…
Integrated photoelasticity in a soft material: phase retardation, azimuthal angle and stress-optic coefficient
Yuto Yokoyama, Benjamin R. Mitchell, Ali Nassiri +3
Integrated photoelasticity is investigated for a soft material subjected to a three-dimensional stress state. In the experiment, a solid sphere is pressed against a gelatin gel (Yo…
An investigation of Hertzian contact in soft materials using photoelastic tomography
Benjamin Mitchell, Yuto Yokoyama, Ali Nassiri +3
Hertzian contact of a rigid sphere and a highly deformable soft solid is investigated using integrated photoelasticity. The experiments are performed by pressing a styrene sphere o…
Droplet impact of blood and blood simulants on a solid surface: Effect of the deformability of red blood cells and the elasticity of plasma
Yuto Yokoyama, Akane Tanaka, Yoshiyuki Tagawa
Previous studies suggest that the behaviour of impacting blood is similar to that of a Newtonian fluid, which has a shear viscosity equivalent to that of blood at high shear rates.…
Origin of Biquadratic Exchange Interactions in a Mott Insulator as a Driving Force of Spin Nematic Order
Katsuhiro Tanaka, Yuto Yokoyama, Chisa Hotta
We consider a series of Mott insulators in unit of two orbitals each hosting spin-1/2 electron, and by pairing two spin-1/2 into spin-1 triplet, derive the effective exchange inter…
Spin nematics next to spin singlets
Yuto Yokoyama, Chisa Hotta
We provide a route to generate nematic order in a spin-1/2 system. Unlike the well-known magnon-binding mechanism, our spin nematics requires neigher the frustration effect nor a s…
Impact of Dzyaloshinsky-Moriya Interactions and Tilts of the g Tensors on the Magnetization Process of a Spherical Kagome Cluster in {W72V30}
Yoshiyuki Fukumoto, Yuto Yokoyama, Hiroki Nakano
In order to clarify why the experimental magnetization curve of the spherical kagome cluster in {W72V30} at 0.5 K shows no sign of staircase behavior up to 50 T, we study the effec…