Presenting realistic tactile sensations in a virtual space requires to provide appropriate stimuli to both cutaneous and proprioceptive senses. This study aims to present high-quality softness sensation by presenting repulsive force and spreading cutaneous sensation according to the amount of indentation. Touch X USB was used as a general force feedback device, and electrical stimulation was used as a means of presenting cutaneous sensation. We measured the change in contact area of flexible samples, and applied an electrical stimulus that reproduced the increase in the contact area of the sample simultaneously with the force sensation. This paper investigated the effectiveness of the fusion of cutaneous and force sensation through a psychophysical experiment and showed that the reality of softness sensation was improved using simultaneous presentation.

This paper presents a circuitry of temperature stimulation using Peltier elements for wearable devices. Peltier elements consume a large amount of current, and when multiple elements are integrated for temperature stimulation, the current consumption reaches several amperes. This is unacceptable for a wearable device, therefore a mechanism for low power consumption is needed. We propose a time-division drive and matrix circuit for Peltier devices to solve these problems. A prototype is used to demonstrate its effectiveness.

To visualize the distribution of tactile pressure, passive matrix (PM) technologies are widely used in a variety of fields such as industrial, sports, and robotics. PM technologies are powerful addressing methods with simple structures, low cost, and easy fabrications, however, have a trade-off between the resolution and the size of the sensor. On the other hand, active matrix (AM) technologies are standard scheme for large/high-resolution flat panel displays to apply certain voltage sequentially on each pixel through switching of thin film transistors. With the insertion of current monitoring circuits, flat panel technologies can be applied for two-dimensional distribution sensors. Here, we demonstrate the possibility of AM technologies for tactile distribution sensors to overcome the trade-off.

Demand for technology to reproduce tactile sensations is increasing in various fields. In order to reproduce tactile sensation, it is necessary to quantify and analyze the tactile sensation of an object and transform it into data suitable for input to a tactile display. We developed a model using Conditional Generative Adversarial Nets (CGAN) to generate an input signal to a tactile display using an ultrasonic transducer, based on data quantified by tactile sensor and human tactile evaluation. In addition, we examined the effect of cluster classification on the input data to the model. As a result, the reproduction of tactile sensation was improved in the model with cluster classification. These results suggest the effectiveness of a vibration data transformation model with cluster classification.

This study aims to reproduce the grasping sensation with a high-resolution suction tactile display. We need a method to generate a suction pressure stimulus based on the strain energy distribution obtained by finite element simulation. In this paper, we aim to obtain information for investigating this method by determining the two-point discrimination threshold of the suction pressure stimulus. The two-point discrimination threshold was obtained by varying the sensation and pressure of the suction holes. The experimental results showed that the two-point discrimination threshold changed depending on the distance between the suction holes and the suction pressure. It was also found that the discrimination threshold was smaller with four holes than with two holes. The results will be used as a guideline for seeking a distributed suction pressure control method based on the strain energy distribution.

In this study, we develop a coated tactile sensor for robots. The accuracy of contact position estimation of this sensor depends on the accuracy of the equivalent circuit model. Therefore, in this paper, we develop a highly accurate model. The capacitance distribution of the piezoelectric film and the resistance distribution of the resistive film are necessary for modeling. The former is obtained by actual measurement, while the latter is estimated using electrical impedance tomography (EIT), a technique for estimating the conductivity distribution of object. In this paper, we discuss how to apply this EIT to our sensors from various perspectives. Then, we evaluated the model by comparing it with an actual sensor. As a result, it was found that reflecting the resistance distribution estimated by EIT and the capacitance distribution actually measured in the model had a certain contribution on creating a highly accurate model.

In this paper, we fabricated a prototype of a grasping-type tactile display that can hold 30 kinds of materials and presents material sensation by moving the materials according to the tracing motion. First, we developed a mechanism that can compactly store many materials by winding a tape to which materials are attached on a rotor and feeding the tape out by rotation. Next, we implemented two functions. One is predicting the next material to be touched, the another is moving the material according to the tracing speed of the finger. Finally, we discussed the contents of the evaluation experiment.

In order to realize a tactile sensor with high temporal and spatial resolution, we proposed a tactile image sensor using an event-based camera. In an event-based camera, each pixel independently responds to changes in the brightness of the environment. Our sensor consists of a black elastic body with nine white markers and an event-based camera. Events are generated when the elastic body deforms and the markers move. We propose to measure instantaneous forces and moments using the event-based tactile image sensor. The maximum or integrated value of the events is used to calculate their estimated values. In addition, we can determine whether it is a shear direction or a rotation direction based on the movement direction of the marker.

Recently, sensory feedback is being expected in many areas uses. Among them, there is force feedback that gives sensory information to humans or systems. Moreover, force feedback is classified as mechanical stimulation and electrical stimulation, especially, electrical stimulation is used in many areas. However, those cannot transmit the force generated in the real world. Therefore, we developed the force feedback device using rotation moment, and we confirmed it can generate a force. In this paper, we describe downsize by component parts changes and material changes for the developed device and evaluation result of force using acceleration sensor while the device swinging.

This paper describes a novel force sensing system using nail deformation. Due to the two strain gauges attached to a nail, the magnitude and direction of the force applied to the fingertips can be measured. We devise a compact and easy-to-install sensor system and also introduce a calibration method. In the proof experiment, several types of basic verification were performed, then the applicability to work using fingertips was investigated.

In robot manipulation, the prediction of gross slip and grasp stabilization control enable complex object manipulation. To realize this, researchers have been studying the use of incipient slip, which is a local deformation phenomenon of the contact surface. However, there are many issues in terms of practicality, because the cost of distributed tactile sensors for detecting incipient slip is high and there are restrictions on the motion state of the robot. In this study, we proposed a method for detecting incipient slip by focusing on vibrotactile sensing and static stick region. In the proposed method, a vibrotactile sensor with a flexible structure and a vibration motor are used to detect the change in the stick region as a propagation characteristic of the injected vibration. In the verification experiment, the proposed method showed an incipient slip detection performance close to that of the distributed tactile sensor, and was able to detect incipient slip even in static conditions that the conventional method could not handle. The method is expected to realize robust grasping control with a low-cost tactile sensor system.

We are developing a mobile manipulator with a small footprint that works in confined spaces such as a home kitchen or a small factory. To perform various tasks, the gripper of the mobile manipulator is equipped with a tactile image sensor using a camera. In this study, we developed a compact and lightweight tactile image sensor that can be mounted on a gripper. Through experiments, we have shown that this sensor is capable of estimating the shear force and determining the contact position. Also, we proposed a method to estimate the direction of door opening based on the direction of the shear force applied to the two fingers.

The ability to localize an object moving in three dimensions without the need for sight can lead to improve spatial awareness and invoke novel experiences. While haptic shear stimulus has been shown to be capable of presenting both mobile and static two dimensional stimuli which can be localized, the presentation of depth using this approach has not yet been investigated. Herein, we propose and evaluate an algorithm for using a rotational skin shear deformation display to present stimuli which can allow one to proprioceptively localize a stimulus source in three dimensions. In the evaluation experiments, we first presented visual stimuli through a Head Mounted Display and then tactile stimuli through the proposed algorithm. The relationship between depth perception, recognition of depth orientation and the range of tactile stimuli was investigated.

We have constructed a haptic display system using a vibrotactile array that presents multi-point vibrotactile stimuli around the waist and a computational model that controls vibration amplitude according to 2D position information. Using this system, we have conducted 2 experiments. The first evaluated the difference in percieved sensitivity of vibrotactile stimulation through a vibrotactile calibration experiment. Results suggests sensitivity of vibrotactile stimulation around the waist is symmetric about the longitudinal axis. Sensitivity adjustment gains were calculated and used in the second experiment. The second evaluated the effect of sensitivity adjustment around the waist on the presentation of 2D position information. Results suggests sensitivity adjustment improves 2D position presentation in some cases.

We searched for new structures that bring about an amplification effect in this work. We discovered the structure for amplification effect from the search results and manufactured the sophisticated designed shape with a 3D printer. Then, we experimented using a ”strain gauge sandwich” to show that the tactile sensation can be obtained objectively. The device can be used for a new ”touch lens” that amplifies tactile sensation in tracing minute irregularities.

In this paper, we have constructed a teleoperation support system that provides simultaneous feedback of force and vibration. Force sensor and acceleration sensor are attached to the robot tip, and the measured values are feedback to the operator. To investigate the effect of force and vibrotactile feedback on the accuracy of stimulus discrimination, we conducted experiments to discriminate materials with stimuli of different hardness and roughness. As a result, we found that the simultaneous feedback of force and vibration is effective for material discrimination.

It is important for autonomous personal mobility(PM) to be able to move in narrow spaces. In this study, we develop a trajectory planning method that takes into account the unique motion model of differtenial-wheeled PMs, e.g., longitudinal body size, inability to move sideways, and inner wheel difference. It inlcudes the use of forward and backward movement, lateral movement by switchback, and sweling movement before turning at a corner. We compared the proposed method with a general path planning method (dynamic window approach) and confirmed that the proposed method does not get stuck.

Personal Mobility Vehicles (PMVs), a new transportation system that links small electric mobility devices with public transportation, is attracting attention for its low environmental impact. Although PMVs called Segway have already been developed, their use on public roads in Japan is legally prohibited. Against this background, a foldable three-wheeled PMV that complies with the enforcement regulations of the Road Traffic Law has been developed in previous studies. However, the vehicle has a problem that the drive wheels suddenly stop during deceleration due to the protection function of the motor. In this study, we improve the driving of the PMV by replacing the motor to a hub motor, which is one of the brushless DC (BLDC) motors. In addition, since it is difficult to install encoders detecting the vehicle speed to the hub motor, we propose controlling the rotation speed of drive wheels using the three-phase sensor of the BLDC motor.

In this paper, we propose a floor surface measurement system for walking assistance with a wearable robot. The point cloud of the floor and an obstacle were measured by a RGB-Depth camera. We assume that most of the points in the point cloud consist of the surface of the floor, and the plane of the floor surface was reconstructed by a principal component analysis (PCA) of the point cloud. The obstacle was reconstructed by the subgroup of the points cloud in which the distance from the floor surface was higher than a threshold. The experimental results showed that the PCA-based method could discriminate of the floor surface and obstacle and could estimate the size of the obstacle.

The ultimate goal of this research is to safely apply automatic driving to Personal Mobility Vehicles (PMVs), which are personal transportation vehicles. One of the problems in applying automatic driving to an inverted pendulum vehicle is that the vehicle requires posture stabilization control at all times. It is important to understand the dynamic motion of the driver during automatic driving. In this paper, we experimentally investigate the driver’s joint moment during manual and automatic turning, and make an estimate formula of the driver’s joint moment. It was suggested that some joint moments are influenced by the elements of vehicle and exforce.

The authors are investigating a hybrid system to improve the driving performance of small competition vehicles. In recent years, model-based development has become the mainstream in vehicle development, and lap time simulation has been attracting attention as a powerful tool to support efficient development, since high vehicle driving performance is important for competition vehicles. By using this tool, complex vehicle development problems in competition vehicles can be converted into lap times, which can provide a powerful criterion for decision making in design and development. In this paper, the prediction of vehicle driving performance by quasi-steady-state lap time simulation is investigated using a detailed vehicle model and an efficient calculation method as a basic study for constructing a control algorithm.

In recent years, the development of personal mobility has attracted attention as a new means of transportation. In previous research, personal mobility with universal design and usability was developed. However, autonomous driving and cooperative control have not yet been investigated. In this study, we propose a hybrid driving method of autonomous driving and manual driving, and develop a cooperative control in personal mobility system based on the degree of danger. The experimental results show that the control switching between manual and autonomous driving is executed properly.

This paper presents the stabilization of a four-wheeled vehicle that has independent suspensions and an universal joint. In the former control experiment, vibratory responses were observed mainly in the chassis and the vehicle was not stabilized. The reason is unmodeled friction effects in the actuators. It is suppressed by using minor feedback of proportional and derivative control. Implementation of the minor feedback takes two steps: converting control input from torque of the driving wheels into their angular acceleration, and tracking the wheel angular velocity to the desired value. The mathematical model is firstly derived and the controller is designed based on the model. The proposed control scheme is verified through numerical simulations.

This paper proposes time-varying Gaussian process implicit surface (TV-GPIS) to estimate the time-varying shape of grasped garbage by a waste crane placed in an Energy-from-Waste plant. TV-GPIS can estimate the time-varying shape by integrating the time-varying Gaussian process and the Gaussian process implicit surface. We first investigated the properties of TV-GPIS for three types of shape transitions in 2D simulation. Then, we present a robotic bucket system we developed equipped with 28 proximity sensors and verified the TV-GPIS’s effectiveness by comparing the volume of estimated shape and grabbed garbage by our bucket.

When working with manipulators in the fields, it is necessary to have 3D information of the work object and its surroundings. When the manipulator is applied to radiation fields, it is necessary to protect the measurement devices, for example, the LiDAR from radiation in its environment. To enforce radiation resistance of the LiDAR, a radiation shielding container for it the LiDAR is developing, in Mitsubishi Heavy Industries, Ltd., with design of labyrinth with conical mirrors to make passes from/to the LIDAR. For the geometrical system formed by labyrinth with conical mirrors, Laser pass analysis were executed and reported.

In this paper, we estimate a motion of a camera and construct a 3D point cloud of a pipe from image sequences in the pipe acquired from the camera at a tip of the robot for an inspection of the inside of the pipe. The 3D point cloud is considered as a cylinder and its radius is calculated. A scale is determined by comparing an actual pipe radius with the point cloud radius. The scale is determined by comparing the actual pipe radius and the point cloud radius. The camera translation is calculated from the scale, and the 3D point clouds of multiple pipes are connected using the translation.

In this paper, we propose a method to improve the accuracy of 3D measurement using a stereo camera by marking objects with a line laser. Stereo cameras are often used for 3D measurement. However, stereo cameras have a problem that the accuracy of 3D measurement is affected by the amount of texture. Therefore, we develop a new measurement system that combines a stereo camera and a line laser. By using a line laser to mark arbitrary points on the object and measuring the marked points, we improve the accuracy of 3D measurement with a stereo camera regardless of the amount of texture on the object.

In our laboratory, as one of the research, we are analyzing the skating movement by small biped robot using a depth camera. But due to characteristics of the depth camera, it has been confirmed that the measurement accuracy of 3D coordinates falls at the remote and peripheral edges. In this study, we developed a system to track the biped robot and measure skating movement using 3WD omni mechanism carriage and depth camera. To improve the accuracy of self-position estimation of the tracking robot, we examined multiple tracking algorithms and implemented appropriate ones. In addition, while expanding the measurable range to 3.0m, it has become possible to measure at the same level as fixed-point measurement. And the cause of the fall was investigated by measuring the state of the fall and quantitatively evaluating the movement.

Generally, in birefringence measurement, it takes a long time to measure because the polarizing element is mechanically rotated. In this study, a single-shot birefringence measuring system for quantitatively measuring birefringence in real time or at high speed, is developed.

The purpose of this study is to save labor in welding. In this paper, we propose a 3D measurement method of welded object to realize automatic teaching for welding robot. With the proposed method, it is possible to estimate the shape, size, position and direction of an object based on a point cloud data acquired from a ToF camera. Experimental results on measuring connection works of building show that the proposed method has effectiveness for automatic teaching. Bounding box estimation method, which is a part of the proposed method, is versatile and expected to be used for other applications.

Entrance is the face of the house, where people and things come and go, and it requires continuous effort to keep it tidy and beautiful. It is also the place where the faces of people coming and going, as well as valuable information and media such as circulars and mail, gather. On the other hand, it is characterized by a relatively small area. Therefore, we are aiming to develop an entrance concierge robot to automate the tasks of organizing items, cleaning, recording information, unlocking, and receiving mail at the entrance.

In this paper, we report the concept of the system and the results of experiments using the object detection algorithm YOLO to recognize shoes for the task of matching shoes at the entrance.

Since the camera has a limited range, it is necessary to use an external device such as a head to move the camera while taking pictures. Although it would be ideal to be able to measure images in any direction of gaze for each frame, this has been difficult due to the response time of the external device. In this study, we propose an imaging method that can select any direction of gaze for each frame based on high-speed scanning of the direction of gaze and exposure timing control, and also propose a principle of parallel random-access vision in the direction of gaze that can measure multiple directions of gaze quasi-simultaneously by realizing this principle with a multi-tap lock-in pixel sensor. The effectiveness of the proposed method is demonstrated by experiments.

We present a light-weight CNN-based object tracker called MobileGoturn. The model resembles GOTURN except that convolutional layers are replaced by a low-cost structure called depthwise separable convolution and a hyper-parameter known as width-multiplier were applied to make a trade-off between speed and accuracy. We incorporated our novel model into a high-speed visual feedback system and demonstrated that the model is comparatively faster to track our proposed target objects in real-time.

Automation of the meat processing is highly desired due to dangers of using sharp cutting tools and involves heavy labor. In this study, we aim to implement the highly accurate method for cut point detection by integrating deep learning in the recognition unit of a meat processing system. The newly developed key point detection method which infers feature point from surrounding patterns was used for detecting cut point in the prime cut process. First, we conducted the preliminary examination of key point detection using existing datasets. However, the detection accuracy was low due to many errors in the teaching points, so we optimized the imaging system and teaching points. As a result, the accuracy of detection was improved to 97.2% from 63.6% at maximum.

In this paper, we implement a novel method to estimate road surface shape and object height using a fisheye stereo camera on GPU for acceleration. Our method consists of three parts, preprocessing, road surface shape estimation and object clustering. Among them, the road surface shape estimation algorithm takes 20 seconds to process because the algorithm is recursive. This is not feasible for real application. Therefore, we change the algorithm to be able to be processed in parallel. We conducted experiment to confirm the difference between the accuracy and the processing time between the previous CPU implementation and the proposed GPU implementation of the approach. It was found that the proposed GPU implementation resulted in 8-times faster processing with no loss of accuracy.

In this study, we propose a novel concept of real-time software rotation sensor that can simultaneously detect the angles of multiple rotational objects in a high-speed video sequence. Our software sensor can be executed in real time at 500 fps by parallel-implementing digital image correlation processes to inspect the similarities among the input image and 360 reference images at different angles on a GPU high-speed vision system. Its performance in measurement accuracy was verified by showing several experiments results for multiple rotating gears that are captured with partial occlusion in 500-fps videos,including multiple gears fast-rotating at 2400 rpm.

Corneal imaging has been studied to estimate the focused object and point-of-gaze by extracting the environmental information reflected from the corneal surface. However, it is also necessary to estimate the self-position as a daily-use device. In recent years, research has been conducted on self-position estimation using interior illumination patterns reflected on the cornea. However, localization based on illumination information was not accurate, and thus, an improvement is required. In this paper, we propose to improve the accuracy of localization by integrating SE-ResNet and IMU on the framework of Monte Carlo Localization.

Automatic pipe recognition is required in the construction of piping BIM models. Commonly, 3D point clouds are used for 3D piping recognition. However, an enormous amount of calculation was required. Therefore, in this study, we proposed a method for pipe recognition using image segmentation networks based on the deep learning technique. To improve the performance of the recognition network, the Attention Mechanism based Decoder and the Rectangular Atrous Spatial Pyramid Pooling are proposed. Through experiments, the performance of the proposed network was evaluated.

P The color temperature of a drone image is affected by the color temperature of the light source, so the color of the drone image changes depending on the time of day and weather conditions. In this study, we proposed a method of color space transformation to change the color temperature of the video in real time. We also applied the color space transformation to a dataset to investigate the effectiveness of the method. The effectiveness of the method was shown by comparing the output image with the test image and the angular error of the corresponding pixels in the images. Verification using a mask image showed that the angular error in the region that requires a certain amount of green light is large. In addition, we proposed a real-time color calibration system using the proposed method.

We investigated the feasibility of using a time-synchronized projector-camera system (SyncProCam) to capture clear underwater images. Underwater images can be blurred owing to the scattering of light by floating objects in water. The SyncProCam allows the camera to only receive projector light reflected from a specific area in space, that is, the area where the object is located. In this study, we presented slit light images to the SyncProCam and a general-purpose camera, and compared the pixel response values obtained by the systems. The experimental results show that the SyncProCam can acquire a higher contrast signal with a lower signal-to-noise ratio.

A method is proposed for tracking pulsating objects by integrating a high-speed, low-latency event-driven camera and a newly developed event-driven particle filter. The event-driven particle filter is an efficient algorithm that computes the input from an event-driven camera as an event representation. It updates the particle state by a state transition model and the particle weight by a likelihood calculation for each event occurrence. The proposed method was evaluated by presenting an event-driven camera with a test video of a target in pulsating motion on a fast-refresh-rate display. The experimental results confirm that the method can estimate the next state in a 1-ms period of the target.

In this paper, we propose evaluation system for on-chip acoustic vibrations. In recent years, microfluidic chip has been researched in the fields of biomedical or biochemical. To manipulate microparticles in a microfluidic chip, acoustofluidics is attracting attention because of its high throughput, low invasive and simple system characteristics. However, temperature variation in the microchannel and diffraction of the acoustic waves cause manipulation force for the particles unstable. In this study, we constructed and improved evaluation system based on schlieren method to investigate acoustic waves in a microfluidic chip. We succeeded in visualizing the standing waves. In addition, the acoustic pressure amplitudes were quantitatively evaluated by obtaining light intensity of the schlieren images.

In this study, we propose a manipulation method of micro/nano particles based on an acoustic radiation force and an acoustic streaming. In recent years, analyses of micro/nano particles are attracting large attention in the fields of medicine or biology. In a manipulation of micro/nano particles, acoustofluidics is a strong candidate because of its high throughput, low invasiveness and simple systems. Manipulation methods based on acoustofluidics consist of acoustic radiation force and acoustic streaming. Acoustic radiation force can arrange microparticles with high precision. On the other hand, acoustic streaming can manipulate nanoparticles with strong force. Thus, we can manipulate both micro and nano particles by combining acoustic radiation force and acoustic streaming. In this study, we fabricated a device to manipulate micro/nano particles by combining acoustic radiation force and acoustic streaming. As a result, we manipulated micro particles by using acoustic radiation force and we observed acoustic streaming were generated.

Regenerative medicine and cell therapy requirs safe and efficient transfection. Optoporation has higher viability and efficiency and it is getting attention. It is important to generalize optoporation by clarifying the dependency of each cell type. However, the dependency on cell types was not clear. We aim to realize intracellular molecular delivery independent of cell type. We conducted experiments using a simple device made of color resist and three types of cells, HeLa cells, HEK293 cells, and A-498 cells, to achieve intracellular delivery. The dependence of the cell type on cell viability and delivery efficiency was characterized.

It is known that Viscoelasticity of culture substrate changes cells behaviors such as differentiation. Hence measurement of local viscoelasticity has been attracting much attention. So far, methods as measurement of local viscoelasticity are mainly VE-AFM and Magnetic Twisting Cytometry. Their methods can measure only surface of samples. Thus, they cannot measure viscoelasticity from inside. In this paper, to measure local viscoelasticity of soft material from inside, we propose a new viscoelasticity measurement method using a light-driven gel actuator. The actuator is driven locally and wirelessly by laser irradiation. We measured of collagen as an example of soft material and confirmed the actuator can move collagen. From these results, we showed that the proposed method has potential candidate for viscoelasticity measurement.

The ground reaction force (GRF) is one of the important factors to clarify biomechanics, and a force plate (FP) is widely used to measure GRF. This paper describes a quad-axis FP that uses mechanical springs and four non-contact displacement sensors. It is expected that the shape and performance of the proposed FP can be easily adjusted. When the force is applied to the FP, the deformations of the springs are measured by four non-contact displacement sensors. The magnitude and direction of forces and moments can be evaluated from the responses of the four sensors. The FP resonance frequency was 123 Hz, sufficient for the GRF measurement. The calibration experiments showed that vertical and horizontal forces and moments could be measured independently. As a result, the proposed FP measured the GRF in four directions during walking.

At the fingertips, there are many tactile receptors that are important for human tactile perception. We are developing a method to estimate the force applied to the fingertip and the incipient slip on the contact surface based on the deformation of the finger pad. It is known that the deformation of the finger pad varies depending on the person and the contact state with the object. Therefore, it is necessary to clarify individual differences in finger pad deformation when the fingertip and an object come into contact. In this paper, we report 3D fingertip deformation using a 3D scan system with a device that can quantitatively press an object to a fingertip. The press device is created by a 3D printer and can keep pressing a finger by a precision stage. From the experimental results, it is shown that the finger pad deformation can be measured three-dimensionally and with high accuracy.

In this study, we present a waterflow sensor for relative waterflow measurement of marine animals. The biologging method recording animal behavior with sensors has been attracting attention in ecology field. However, there is not a sensor that can measure relative waterflow for long time period due to the stringent requirements for miniaturization and pressure resistance. In addition, marine animals move above the sea surface to breath. Here we proposed digitized compact Pitot-static-tube-based waterflow sensor for biologging of marine animals. Incompressible liquid is sealed inside the sensor to realize high pressure resistance. Silicone rubber is attached on inlets of the sensor to prevent air bubble intrusion. This sensor has a differential pressure (DP) sensor element inside and measure differential pressure between each inlets. By downsizing sensor size and digitizing DP sensor element, the sensor became adaptable to more marine animals. The developed sensor responded differential pressure from 0 to 5 kPa with sufficient sensitivity.

In the studies of seabird ecology during the breeding season, a baby bird was captured many times to measure the body weight. This not only affected the breeding, but also made it difficult to accurately measure the weight change of the baby bird. Here, we propose a scale for long-term and sequential measurement of the seabird weight in the nest. The scale consists of spring structures and a non-contact displacement sensor. Since the spring structures and the sensor element are separated, the specifications of the scale can be easily changed by adjusting the spring structures. The sensor element is an eddy current displacement sensor, which has environmental resistance and can be used in harsh natural environments. The experiment to evaluate the specifications of the scale showed that the force range was 2 kg and the resolution was 4.2 g.

This paper describes a micro scale using a polyimide film-based force plate for measuring the weight of fruit flies. The proposed sensor consists of a spiral coil spring and a laser displacement meter. As a force applied to the center plate, the spiral coil spring bends vertically and generate vertical displacement. By measuring the spring constant and the displacement, the applied force is calculated. We used a polyimide film as the device material so that the force plate realized the low spring constant and high durability at the same time. The fabrication process is easier compared to that of the conventional MEMS force sensors. The spring constant of the fabricated devices were sub-N/m, and the force resolution became less than 0.02 μN.