This study reports the sensitivity characteristics of a waterproof airflow sensor for seabird biologging. The alumina membrane with a nano-hole array is attached to the inlet of the sensor to obtain a waterproof function. Waterproof function increases with decreasing pore size of the nano-holes due to Laplace pressure. Here we confirmed that the sensitivity decrease was due to air leakage from the cantilever-type sensing element. Furthermore, we theoretically and experimentally evaluated the sensitivity was determined by the air mass flow ratio through the membrane and the cantilever element. The flow through the membrane was directly proportional to the membrane area and was affected by the pore size. Thus, we can determine the pore size of the nano-hole that optimizes the water pressure resistance and sensitivity.

Ingestion of food and water is an important item related to the basis of human life support. However, with aging, oral sensation and saliva secretion decline, making it difficult to swallow, causing food to suffocate in the throat, or to enter the lungs and cause pneumonia, causing "aspiration" in the elderly. In many cases, it can be life-threatening. Such aspiration in the elderly can be prevented by preparatory exercises such as relaxing and training the muscles of the face and neck. In addition, a screening test to quantify the effect is also indispensable. Therefore, in this study, we developed a simple non-contact type sensing system for swallowing motion using only a camera.

This study proposes an open silencer utilizing a Helmholtz resonator (HR) array to reduce blower noise. Most blowers generate uncomfortable high-frequency noise due to their high-speed rotating parts. However, the conventional passive noise control (PNC) method using a physical sound insulator reduces their airflow. The proposed HR array plate consists of HR elements and penetration hole elements densely arrayed like a honeycomb structure. Multiple HR elements arranged around the penetration hole effectively attenuate the noise in the resonant frequency. Due to the high aperture ratio, the HR array plate insulates a noise without blocking airflow. The prototype device realized a 10 dB reduction in 2 ~ 4 kHz, where the noise spectrum of a typical blower has a peak.

We have proposed a human-machine system in which a teleoperation robot realizes movements that transcend the athletic ability of the operator, based on a visual prediction that predicts the future a little ahead. In this paper, we investigate whether the system affects human motor learning through subject experiments. The results of the subject experiments suggest that motor learning can be enhanced by presenting motor sensations that greatly exceed the learning capacity of humans.

We have developed a real-time vibration imager that can simultaneously visualize vibration distributions at all frequencies by calculating frequency responses of brightness distributions, sub-pixel displacements, and velocity distributions through parallel GPU implementation of various signal processing such as short-time Fourier transforms for high-frame-rate images acquired with high-speed vision.

Compared to 30 years ago, motor skills of Japanese children have decreased. On the other hand, the height and weight have increased, and when considered as a musculoskeletal system, modern children are more developed. Nevertheless, motor skills have decreased, in order to solve the problem of decreased motor skills, it is important to improve not only the development of physical constitution but also the motor control skills. Thus, we focused on the sense of rhythm which is considered to be one of the motor control skills. In this study, we evaluated the human stepping rhythmic movements instructed by sound signals, conducted experiments twice a week for 4 consecutive weeks, and analyzed the improvement in rhythmic sense over time. We report the results.

In this study, we propose light driven gel valves for high integration. Previously, we proposed drive method of gel actuator with light irradiation. Temperature responsible gel was used for actuator material in this method. Moreover, this method can realize local heating with focused light and thus, realize independent drive of single actuator even if multiple actuators are arranged. By using these actuators, we fabricate highly integrated gel valves. We fabricated four types of gel valves with different shapes and arrangements. Gel valves are designed based on measurement of the volume expansion rate of gel actuator. As a results of open/close evaluation, gel valves with squared shape and arranged both channel sides were suitable for high integration. In the future, we will integrate large number of gel valves and apply various applications to these valves.

A droplet-based micro total analysis system (μTAS), which handles sample/reagent in the state of droplets, is expected to be practical in biochemical analysis in recent years. The typical components essential for droplet-based μTAS include a pump, a mixer, a sorter etc., and they are ideally embedded on a chip. Hence, this study aims to realize an on-chip droplet sorting system mediated with an electro-conjugate fluid (ECF) flow contributing to droplet-based μTAS. The ECF is a kind of dielectric liquid generating a strong flow when subjected to high DC voltage, making it possible to integrate a fluid power source on a chip. The experimental result revealed that a droplet generated on a chip by T-junction was successfully sorted by the developed droplet sorting device driven by the ECF flow.

Analysis of cell-cell communication is attracting large attention in the field of cell biology or immunology. However, the conventional methods of analyzing cell-cell interaction are not suitable for cell-cell interaction in group cell. In this study, we propose a flow control and manipulation method for cell transport and trap toward analyzing cell-cell interaction by using integrated light-driven gel actuators. We construct an electronic-hydraulic analogy for switching streamline by using integrated light-driven gel actuators. We confirmed the switching of the streamline based on the constructed model. Furthermore, we succeeded in manipulation of multiple cells, transport and trap. From these results, we show potential of the proposed method for analyzing cell-cell interaction in a microfluidic device.

Cell preparative systems are required to have multiple selectivity and high speed. However, most preparative systems are limited to two selective preparations. Therefore, we have developed a cell preparation system with multiple selectivity and high speed using a femtosecond laser.

The micromixer we are developing generates the swirling flow inside the main chamber by vibrating the silicone wall between the main chamber and the driving chamber with pressure vibration. In this research, the proposed mixer is enlarged to be able to stir the spheroid and the reagent in the main chamber. The mixer developed in the previous research is too small to insert the spheroid. However, the enlargement of the mixer keeping with the similar design in geometry causes a decrease in the stirring flow. The mixer was redesigned by focusing on the aspect ratio of the silicone wall in order to solve the problem. As a result, it was confirmed that mixing was possible in the main chamber that can be inserted spheroids inside it.

This paper proposed a high-speed control system of air-liquid two phase flow to change osmotic pressure in a microfluidic device. In particular, we measured the osmoadaptation of the single cell at the high time resolution over 1 ksps. Conventional studies utilized optical density and stopped-flow spectrophotometry methods, which only showed the response of cell population. Another representative method utilized a microfluidic chip having patterned hydrogel to measure the osmoadaptation for each of single cell. However, it was still difficult to measure the osmoadaptation for a single cell with high time resolution. Therefore, we developed the high-speed solution replacement system to change cell suspension into different osmolality solution using at the volume of 10 pL order droplet. We sought the design strategy of droplet formation and high-speed solution replacement in the microchannel. From the experiment, the solution replacement time of 3.3 ms was achieved. Finally, we demonstrated the proposed microfluidic system that could measure osmoadaptation of single cell under sudden osmotic pressure change.

In this work, an FPGA-based impedance cytometry is proposed to characterize the morphology and interior of single cells. When the detection frequency is sufficient to penetrate the cell membrane (6 MHz), uneven intracellular component distribution can alter morphology of impedance pulses. When the frequency is below 1 MHz (500 kHz), the morphology of low-frequency impedance pulses is related to the shape of single cells. Additionally, the magnitude of impedance signals (500 kHz and 6 MHz) gets the dependence on the cell volume and interior biomass, respectively. The detection method is label-free and high-throughput, and successfully demonstrates the ability to track changes in biophysical properties

Micro Mixer Driven by Elastic Side Wall is easy to make and can control mixing, but the details of the transmission of driving force have not been clarified. In this paper, we focused on the vibration of the connector tube and compared the mixing performance by varying the vibration conditions of the tube. The experimental results showed that the change in tube vibration affected the mixing performance, indicating that the connector tube contributed significantly to the transmission of driving force. It was also found that the vibration of the connector tube was suppressed at the connection with the microchip. The above results suggest that it is possible to design a micromixer that achieves arbitrary mixing performance by appropriate selection of tubes, but this requires detailed analysis of tube constraints and transmission of driving force.

In recent years, environmental pollution caused by microplastics has attracted considerable attention. We have been examining the applicability of acoustic focusing for the collection microplastics. In this study, we fabricated a microfluidic device to concentrate microplastic suspension over 100 times. We designed the microfluidic device to focus microplastics at the center of the channel by acoustic force and flow into the center channel of trifurcated branches. Also, we designed microfluidic channel to flow 1/3.2 of the total flow into the center channel. After four trifurcated branches, microplastic suspension is concentrated over 100 times. We evaluated the collection performance of the device experimentally. Polyethylene microparticles about 50 μm in diameter were used as model microplastics. The device was able to concentrate the microparticles over 100 times at the flow from 1 to 7 mL/min.

We developed a device to reproduce malignant transformation caused by nutrient deprivation inside a cancer cell aggregate on the outside of the aggregate where it can be easily observed. We modified the fabrication method of the nutrient-supplying alginate gel fiber so that it could be fabricated inside the device, which facilitated the assembly of the device. The effect of the change in the fabrication method of the nutrient-supplying alginate gel fiber on the cell culture was investigated, and it was confirmed that the ingredient of the alginate gel fiber does not affect the survival rate of the cell.

For drug discovery and pathological research of NAFLD using liver organoids, it is essential to measure local multi-parameter which are closely related to organoid status such as pH, temperature, and dissolved oxygen concentration inside the liver organoids to evaluate the fibrosis and inflammation of organoids. In this study, we proposed a multi-parameter measuring system equipped with a quartz culture well for fixing liver organoids, probe-type microsensors, and two-way observation system. Measuring system is installed in a clean bench and measures the force, pH, dissolved oxygen, etc. of organoids. In system, these wells which were embedded liver organoid are operated by a Robot Arm for automated transportation and sorting. Here, the effectiveness of the system was confirmed by experiments measuring the dissolved oxygen concentration inner liver organoids with different degrees of fibrosis.

We investigate how predictive vibratory-interoceptive stimuli in context with audio-visual contents affect viewers’ emotional experiences. We hypothesized that mechanical vibration to the upper body would stimulate visceral sensations, which would in turn act on interoception sensations and change emotions. In the experiment, the vibration was presented with Predictive scene in horror videos. Predictive scene is a scene that predictively suggests emotional arousal, and is in advance of a jump-scare scene that intentionally surprises the viewer and causes emotional arousal. The effects of predictive vibratory-interoceptive stimuli were discussed in terms of the viewers’ physiological response and subjective ratings.

In remote communication using a videophone, it is expected that by transmitting haptic information including temperature sensation, a mental connection and a sense of security can be obtained in the same way as when meeting in person. However, the conventional haptic transmission system has a problem that a dedicated system for transmitting tactile information together with video and audio is required. In this research, we constructed a system that transmits not only vibrotactile sensation but also temperature sensation by utilizing the existing voice call system. From the roughness and temperature discrimination experiment, it was clarified that the proposed system can transmit the difference of roughness and temperature of an object.

The control of human motion depends heavily on tactile sensation, hence it is important to understand this sensation digitally in the analysis of the motion such as grasping. When representing tactile sensation digitally, a sensor that converts the grip force, bending, and torsion generated during grasping into data is necessary. In this study, an ultra-small tactile sensor was embedded in a flexible elastomer sheet, and its response to applied force, bending, and twisting was measured and investigated. As a result, it is demonstrated that this sensor can be used to obtain responses not only to force but also to the amount and direction of bending and torsion.

In recent years, learning using tactile technology has been developing along with research using Virtual Reality (VR) technology, but VR is expensive and cannot be easily prepared for. Therefore, in order to generalize learning using the sense of touch, we thought it necessary to use tablet terminals and other devices that we possess on a daily basis. A method of dynamically displaying text by tracing a finger on a display has been proposed. In this paper, we present vibrations to the finger during the display of text by this tracing action, and verification the effect of tactile stimuli on learning.

Understanding the mechanisms of weight illusions lead to effective presentations of weight perception. This paper investigated a weight illusion caused by simple vibration applied to the fingertip from the perspective of grasping force. Five vibratory stimuli with different frequencies from 30 Hz to 300 Hz were tested, and the change in grasping force and the intensity of the weight illusion caused by the vibratory stimuli were investigated. The lower the frequency of the vibration stimuli, the higher the grasping force and the reported weight illusions. These results suggest that the presentation of a single vibration stimulus increases the grasping force and makes the object feel heavier.

This study aims to investigate the psychological effects that occur when adding vibrotactile stimulation to remote communication. To make sure the psychological effect happened from vibrotactile stimulation; we conducted an experiment using an emotional synthetic voice adding vibrotactile stimulation. For the stimuli, we recorded vibrations of knocking the board device at 80,100,120,140 BPM rhythm and presented them along with anger and cheerful emotional womanized voices. Results showed that, vibrotactile stimulation affects how positive or negative the synthetic voice sounds. For a slow rhythm, the voice sounds was perceived negative and at a fast rhythm, the voice sounds positive. We think that the vibrotactile stimulation can take part of nonverbal information in remote communication.

This paper developed 6Dof finger-mounted kinesthetic display for rendering force and torque cues simultaneously. The display is a modified model of the basic 6RSS parallel link mechanism by improving with redundant rotational joints. Comparative experiments show that the operating range of the improved model was larger than that of the basic model.

This paper constructed a tactile display system using multi-point vibrotactile stimuli on the head and waist and computational model that continuously controls the amplitude of multi-point vibration according to three-dimensional position information. Through experiments using the constructed system, the presentation performance in the dimensions of depth, orientation, and height is evaluated. As a result, the system was able to present 3D positional information, and its effectiveness was demonstrated.

Linear Resonant Actuators (LRA), which are commonly used for smartphones and game controllers, can stimulate high-frequency vibrations, but it is difficult to present low-frequency ones. We found that a single sinusoidal waveform signal in voice coil actuators, which is higher frequency than the bass signal, can represent a low-frequency-like sensation. This paper investigates this phenomenon and verifies whether it can be used as a low-frequency vibration alternative representation method. The experiment result shows that this method can present the low-frequency sensation perceived by the low-frequency vibration presentation of 10 Hz and 20 Hz by using the alternative stimulus with the frequency range of 60 Hz to 100 Hz, which is relatively high frequency.

This study analyzes the recognition process of examining the texture of fine particles through tactile sensing using human fingers and aims at establishing the structure of texture recognition. The research aims to investigate the occurrence of hysteresis in tactile sensation in mid-teens. The results of the sweep experiment in this study confirmed the existence of hysteresis in tactile sensation in mid-teens.

The purpose of this study is to measure pressure during hugging using a female mannequin of 70-year-old model. And we examined pressure distribution on the body surface. The mannequin was covered with a sheet-type pressure sensor, and the participants in the experiment hugged the mannequin to measure the pressure received when the mannequin was hugged. From the measured pressure, the pressure distribution applied to the body surface when hugged was found. As a result, it was found that when we usually hug, we feel pressure on the whole body, but actually the pressure is applied to only a part of the body. This result will help in the future development of hug-related devices.

Recently, the demand for technology to remotely transmit haptic experiences related to skills has been increasing. This study attempts to convey a haptic experience with tactile sensation by reproducing the spatial patterns of vibrations generated at the wrist using a bracelet device with multiple sensors and vibrators. This paper investigates the human discrimination capability of haptic experiences during different whisking motions by comparing the bracelet device with a conventional tool-mounted device. We also investigate the effect of the ISM method, which can modulate the waveform to lower frequencies while maintaining the original sensation. The results indicated that reproduction of spatial distribution by bracelet device improves discrimination of differences in the rotation direction, and ISM further improves the discrimination of directional rotation compared to the raw signals.

Haptic-based texture exploration is used to create products in modeling software. However, conventional haptic modeling methods can only reproduce the measured texture. In this research, we synthesized the texture vibration by shaping the white noise with a parametric equalizer (PEQ). The parameters of the PEQ (fundamental frequency, bandwidth, and gain) are stored in a three-dimentional LUT(Look-ip Table) of force, velocity, and texture characteristics as roughness,... and density. By approximating these LUTs using the multidimensional least-squares method, it is possible to generate a tunable haptic texture model. In this paper, we propose a haptic synthesis system using PEQ and discuss the synthesis results in the velocity axis based on sensory tests.

Many studies use electrical muscle stimulation as haptic feedback. There are vary electrodes used for electrical muscle stimulation (EMS) depending on the size, material, etc. However, few study quantitatively evaluate the characteristics of electrodes, and a lot of them are based on empirical facts. In this study, we focused on the resistance values of the electrodes and the human body, and evaluated the electrodes suite for EMS. As a result, we found that the electrode made of conductive rubber causes much pain and it is unlikely to be suitable as an electrode for electrical muscle stimulation. On the other hand, gel-type electrodes are suitable as electrodes for electrical muscle stimulation because they can suppress pain.

In recent years, VR technology has developed remarkably and is drawing attention. HMD is indispensable for VR experience. When the HMD is worn, sweating causes the inside to get stuffy, causing VR sickness and heat stroke. In this research, we will develop an HMD with a ventilation function and aim to improve the comfort by blowing air into the HMD. We investigated the ventilation method and the ventilation route for sending wind into the HMD. Then, three types of wind, steady wind, rhythm wind, and 1/f fluctuation wind, were implemented, and the comfort feeling was evaluated using principal component analysis. When two types of evaluation experiments, an exercise task and a video task, were carried out, it was found that the rhythm wind was effective for the exercise task and the 1/f fluctuation wind was effective for the video task.

In Japan, robotic automation has been introduced to solve the labor shortage, and universal gripper with tactile sensing is one of the automation interests.Universal Vacuum Hand(hereinafter, UVH) has been developed as the universal hand with sensing which the resistance of conductive powder changes with density. In the preliminary study, UVH with mixed powder of the conductive and non-conductive ones are effective for measuring the force applied to the sensor, but the noise effect was cause the evaluation error. In this study, we improve the circuit using the four-terminal method in order to measure the resistance value accurately. Furthermore, we also evaluate whether the jamming transition has the effect to the resistance depends on vacuum pressure.

In recent years, the electrical devices have become increasingly diversified and varied, with their specialized interfaces with solid and fixed shape and number of inputs. As a result, the usabilities of the interfaces vary depends on person that is difficult to optimize it for the person, even if the person is desired. Therefore, flexible and shape memorizable interfaces based on jamming transitions have the potential to adapt to each individual user for optimal usability. In this study, we propose a Universal Jamming Interface (UJI) based on a jamming transition sensor. The proposed UJI uses a conductive powder for tactile sensing. The piezoelectric properties of the UJI were evaluated under concentrated load and sensor stretching.

The UVH is a gripper that combines the functions of a vacuum suction cup, a jamming gripper, and a sensing function. The UVH is a gripper that has several electrodes in the membrane and is filled with conductive powder to measure the electrical resistance between the electrodes, which enables us to grasp the contact between the gripper and the object being grasped.

In this study, we measure the electrical conductivity and bulk density of several kinds of conductive powders against the load using a powder volume resistivity measuring device, and measure the gripping force when the powder material is filled inside the gripper using a pressing test machine. Based on the above experiments, we aim to clarify the most suitable conductive powder for UVH.

In recent years, many tactile displays have been developed. Haptic displays based on tactile information obtained from actual textures have high reproducibility. However, since these contents reproduce tactile sensations based on recorded information, it is necessary to record tactile information from actual textures in order to extend the contents. To solve this problem, we propose a method to generate uncollected tactile information from existing tactile information using Generative Adversarial Network (GAN). In this paper, we generate new tactile vibration information by learning 3-axis acceleration information obtained from actual textures using GAN and combining two existing tactile information. By creating a spectrogram of the generated haptic information, we visually compared and verified the changes in features caused by the ratio and combination of the haptic information.

We have proposed a stereo vibration technology that localizes the position of the feeling of vibration sources in the external world like stereo acoustics. Similar to the amplitude panning method in 3D acoustics, the stereo vibration localizes the vibration source by distributing the psychological intensity of the vibration to multiple vibrators according to the position of the source. The proposed method calculates and distributes the perceived intensity of arbitrary waveforms, including high-frequency ones, using the Intensity Segment Modulation proposed by the authors. This paper investigates the discrimination performance of the proposed method for moving trajectories of a vibration source by simultaneously controlling the direction and distance of the source.

In this work, a pressure sensor was manufactured by a simple screen-printing method and used as a tactile sensor for a robot gripper. Two-dimensional pressure mapping information was obtained by arranging the sensors in a 4x4 array. By integrating with a wireless communication circuit equipped with a Bluetooth Low Energy (BLE) module, it can be easily attached to a robot gripper. The gripping force of the robot gripper was controlled using the obtained sensing information, and non-destructive gripping of soft objects was realized.

This article proposes a method of configuring a two-stage mechanism with a wide range of motion and wide bandwidth control by adding a one-degree-of-freedom actuator with a narrower moving range but wider control bandwidth to a general-purpose manipulator. Then, the proposed band-separation control system is implemented in a manipulator with a linear actuator, and its effectiveness is verified by comparing it with conventional methods, constructing impedance control as an example. As a result, it was confirmed that the proposed method can reduce the displacement of the second stage compared to the conventional methods, and can achieve an impedance characteristic of an equivalent mass of 50 g in a wide moving range. Furthermore, as an application of the proposed method, a haptic interface based on variable impedance control was implemented and its performance was evaluated.

We have developed the twin-drive MR fluid actuator (TD-MRA) by using two MR fluid clutches and single motor for fine haptic interfaces. In our previous project, this actuator was utilized in a follower system of a remote-controlled surgical simulator. To expand its usability and application, we proposed a generally usable haptic interface by combining a delta-type structure and three TD-MRAs (DH-MRD). In this study, we evaluated and discussed its force control performance.

In recent years, force feedback devices have been developed to improve the reality of VR experiences. However, most of the general force feedback devices target the upper limbs. By realizing force feedback to the lower limbs, it will be possible to realize an experience in VR space that cannot be achieved by force feedback to the upper limbs alone. Therefore, the authors aim to develop a lower limb force feedback device. In this study, we developed a lower limb force feedback device based on a physical model at soccer kicking. The output torque of the developed device was confirmed that met the target torque by the experiment.

In recent years, force feedback devices have been developed to improve the reality of VR experiences. However, most of the general force feedback devices target the upper limbs. By realizing force feedback to the lower limbs, it will be possible to realize an experience in VR space that cannot be achieved by force feedback to the upper limbs alone. The authors have clarified the perceptual characteristics of the human dropping sensation in order to present force feedback to the lower limbs. In this study, we developed a wearable force feedback device that can present the sensation of dropping in VR space.

This study develops a real-world haptization system based on high-speed active vision that can virtually touch a remote human-untouchable object vibrating at the audio frequency level such as product machines operating at high speed and heated systems in factories. A high-speed active vision system can simultaneously observe small vibrations at hundreds of Hertz by executing digital image correlation analysis with sub-pixel accuracy in real time at 500 fps. A remote user enables wide-angle observation by operating its pan-tilt mirror direction with a trackball interface, and virtually feels the vibration by exciting his finger with a high-speed one-axis vibrator. Several experimental results show the effectiveness of our vibration haptization system that enables remote touch on human-untouchable vibrating objects such as a boiling electric kettle, a heated boiler, and a fast-rotating pump motor.

The Airborne Ultrasound Tactile Display (AUTD) produces tactile sensation remotely on a human skin by controling the sound pressure distribution. However, it is difficult to produce tactile sensation to areas which are shielded from ultrasound. In this paper, we propose a method for produce tactile sensations to shielding areas by using curved reflectors. Using a hand and reflectors shape as mesh models enables to calculate contribution from reflection on curved reflectors. Fast Multipole Method (FMM) reduces memory usage and it enabled calculation. By simulations and experiments, we confirmed the feasibility of producing focal point by using reflection on curved reflectors.

Three-dimensional (3D) haptic devices are expected to be applied to various fields such as haptics in the metaverse. Conventional 3D haptic devices consist of many actuators and mechanical elements, therefore, they need a large and complicated structure for 3D haptic display. In order to solve these problems, we have been developing a 3D haptic actuator that can be driven in various directions in space by only one actuator with compact size. This paper describes its structure and operating verification. The experimental verifications of the partial acceleration response for haptic display are shown.

In the field of social psychology, many studies have been conducted to clarify human cooperative behavior using experimental games. In this study, we developed a Haptics interface that can share the input actions of others in real time, assuming communication in an online environment. And investigated the effect of sharing physical information on decision-making in an experimental game played by multiple players.

With the development of 3D printer technology, it has become possible to reproduce surface shapes. However, the methodology to reproduce the desired tactile sensation has not been sufficiently studied. In this study, we measured the surface shape of canvas and tried to reproduce the surface shape using a 3D printer. Then, we conducted a grouping experiment of the tactile sensations and evaluated the similarity of the tactile sensations using the multidimensional scale construction method.

The number of opportunities to communicate online, including calls and live streaming, has increased in recent years. However, online communication often gives a different impression to the other party than the one you want to convey. Therefore, I decided to study the effect of sound visualization on the impression of speech. Therefore, I conducted an experiment to try to visualize the sound using speech spectra.

We propose a metal mesh structure as an electromagnetic shield for an airborne ultrasound tactile display (AUTD) which manages both low electromagnetic emission for fMRI-compatibility and ultra-sound transmission. Focusing on designing of the mesh pitch, aperture rate, and number of sheet, we verified both electromagnetic shielding effect and sound intensity attenuation rate by numerical simulation. Also by measuring the magnetic field radiation from the AUTD and comparing it with the reference value of the previous research, it was confirmed that 70 dB atttenuation is required for shielding. Comparing these result, we found that the most appropriate shielding structure of the mesh has three layers, 0.9 in aperture rate, and less than 0.2 in rate of pitch to wave length. The simulation result can be also applied in electromagnetic shield for other devices having compatibility of low intensity of electromagnetic wave with sound transmission.

In this paper, we propose a tentacle-type soft actuator used for a highly flexible end-effector that can be applied to microscopic operations required for AI robot systems. For AI robotics platforms, it is required to develop end-effectors that can manipulate microscopic objects such as cell, organoids, oocytes. In addition, as a next-generation soft actuator, a device that mimics an octopus foot is attracting attention. However, there is a limit to miniaturize due to the pneumatic or hydraulic drive. Therefore, we have developed a soft actuator which be used for microscopic operations. The proposed device employed silicone rubber as a structural material, a variable stiffness actuator combining shape-memory alloy and shape-memory polymer, and a suction mechanism using shape-memory polymer. We demonstrated feasibility of the proposed device for microscopic operations.