Ohmi Fuchiwaki

Multi-axial micromanipulation organized by versatile micro robots and micro tweezers

In this paper, we describe development of the multi-axial micromanipulation organized by versatile micro robots using micro tweezers. To conduct microscopic operations, a unique locomotion mechanism composed of four piezoelectric actuators and two electromagnets is proposed. Here two legs arranged to cross each other are connected by four piezoelectric actuators so that the robot can move in any direction, i.e. in X and Y directions as well as rotate at the specified point precisely in the manner of an inchworm. To manipulate micro objects by these versatile micro robots, we have developed micro tweezers driven by 3 piezoelectric actuators. We have also developed an electromagnetic spherical micromanipulator to position the micro tweezers. The electromagnetic spherical micromanipulator rotates in yaw, roll and pitch directions independently. The electromagnetic spherical micromanipulator is a 1-inch cube size, so we can easily attach them on top of the versatile micro robots. We have developed the multi-axial micromanipulation organized by 3 versatile micro robots with the electromagnetic spherical micromanipulator and micro tweezers. The whole manipulation device is very small, 200 mm in diameter and 70 mm in height, so we can easily attach the device to micro processing instruments even if the working area is very small. This device has 21 DOF with less than 100 nm resolution. In experiments, we have demonstrated flexible handling of miniscule glass spheres with a diameter of 20 mum. We have also succeeded in fixing miniscule glass spheres on a sample table by an ultraviolet cure adhesive. The design procedure, basic performance and micro-assembling applications of this tiny robot are also discussed as part of the new field of micro robotics requiring especially high precision in certain regions.

Flexible micro-processing by multiple microrobots in SEM

We describe the newly developed flexible micro processing system assisted by 1 inch size robots in the scanning electron microscope (SEM). The basic performances of the small robot composed of piezo-elements and electromagnets are presented and then the magnetic shield property is considered to prevent the SEM image distortion due to magnetic flux. In order to handle some small objects, an electrostatic micromanipulator driven by the piezo-bimorph is also incorporated on the robot. The small sliding table on the robot can transport them at SEM focusing point accurately. This arrangement can allow the X-Y accurate positioning at any location within the chamber. On the sample table, a micromanipulator from another small robot can pick up and down the small objects simultaneously. In addition, the fiber guided YAG-laser is also employed to provide the micro-material abrasion. The operator can control each small robot easily with the help of the real time monitoring of SEM image and the PC assisted interface.

Development of 3-DOF Inchworm Mechanism for Flexible, Compact, Low-Inertia, and Omnidirectional Precise Positioning: Dynamical Analysis and Improvement of the Maximum Velocity Within No Slip of Electromagnets

In this paper, we describe the dynamical analysis and improvement of the maximum velocity within no slip of electromagnets for a 3-DOF inchworm mobile mechanism. The mechanism consists of four “Moonie” piezoelectric actuators and a pair of electromagnets and moves like an inchworm with less than 10-nm resolution. We calculate the dynamical relationship among 3-DOF motion, four piezoelectric displacements, drive frequency, magnetic force, mass of electromagnets, and spring constants of mechanical amplifiers. We also calculate the maximum velocity with no slip of electromagnets because the no-slip condition is significant for positioning repeatability. In several experiments, we have checked the theoretical validity and positioning repeatability. The design procedure, basic performance, and chip-mounting applications are also discussed for cultivating flexible, compact, low-inertia, and omnidirectional precise positioning technology.

Micro hopping robot with IR sensor for disaster survivor detection

Collapsed buildings due to earthquake or terrorist attack typically result in a rubble pile with access holes less than 1 foot in diameter. The necessity of producing smaller robots which can locate survivors quickly is evident in light of recent disasters and attacks. In the reported research, instead of developing one or two expensive robots, the proposed concept is to manufacture thousands of less expensive micro robots (<

A Development of Dispenser for High-Viscosity Liquid and Pick and Place of Micro Objects Using Capillary Force

10/micro robot) which can access small openings in the rubble pile. Therefore, the probability of locating survivors increases exponentially due to the exponential increase in the number of robots and because these smaller micro robots can move through small openings which larger robots are not be able to access. Key to the approach is to place the micro robots at the top of the rubble heap so that little energy is consumed as the micro robots search downward (carried by gravity) when not utilizing their own power source. In this report, small hopping robots which have a simple locomotion mechanism and IR sensory elements have been developed to detect survivors under collapsed buildings. This small robot includes micro eccentric motors for generating lift and thrust forces, and IR sensors for detecting the thermal signal of survivors. Therefore, the micro robot can crawl without any wheels or legs even on small, rough terrain with the help of eccentric mechanical vibration. This tiny robot also has the ability of self-righting to allow it to keep moving to the target even if it falls and lands in any position. Weight balance as well as resonance parameters are very important to achieve good mobility. Automatic navigation to the target is achieved with simple on-off motor switching. The simple design layout results in not only lightweight robots but also low cost allowing employment of a large number of robots in the dangerous rubble field. Initially, a small robot utilizing off-the-shelf components (i.e. micro motors, button batteries, sensors and electronics) was designed and assembled to verify feasibility for rescue operations. In the initial experiments, many small robots with optical and IR sensors have been developed and movement toward a human body under zero light conditions has been successfully demonstrated.

Development of the Orthogonal Micro Robot for Accurate Microscopic Operations

In this paper, we describe the development of a needle based dispenser for high-viscosity liquid, and pick & place of micro objects using capillary force. Recently, miniaturization of portable devices and their electronic parts has been remarkable. So we think that there are a lot of needs for micro manipulation for making more complex and smaller devices. There are a lot of possibilities to manipulate complex-shaped micro objects by using liquid because it changes its shape flexibly according to the shape of the contact surface. We have developed a unique surface mounting technology which is based on a movable shaft driven by a piezoelectric linear motor. We can simply apply high-viscosity liquid drops by stamping the wet tip of the shaft on a substrate, and we confirm that the device is able to apply a liquid the viscosity of which is about 1200Pas. We have studied the relation between viscosity and diameters of applied liquid drops via several experiments. We have also conducted interesting experiments in which we pick and place some small and complex-shaped objects using capillary force. We confirmed that if capillary force between the shaft and micro object is larger than that between the substrate and the micro object, we are able to place a chip-capacitor weighing below 1 mg. This simple method is very effective because any shaped object can be mounted. However, fast control and accurate control of the shaft are needed for efficient production and accurate mounting. To realize this, we developed a PID controller for the dispenser with an optical liner encoder with a resolution of 30 nm. We confirm that settling time becomes less than 50 ms when the shaft moves 5 mm with 1 micrometre accuracy.

Desktop Micro Machining System by Multiple Micro Robots

In this paper, we describe development of an orthogonal micro robot for accurate microscopic operations. In order to provide microscopic operation, the simple locomotion mechanism which is composed of one piezoelectric actuator and two U-shaped electromagnets is proposed. Here two U-shaped electromagnets guided by a pair of v-grooves are connected by a piezoelectric actuator so that it can move in one axis precisely. This simple one-axis micro robot moves like inchworm with less than 100 nm resolution. We attach permanent magnets on the electromagnets so that this robot can fix itself on a steel surface even if we do not apply the current to electromagnets. In order to provide XY orthogonal positioning, we connect one micro robot to another micro robot orthogonally. In order to realize cell-processing, we attach the three orthogonal micro robots on an inverted microscope. Here we attach a micro pump to a left micro robot to hold biological samples such as an egg cell. We attach another micro pump to a right micro robot to inject to biological samples. We arrange another micro robot between other two micro robots to position samples. The whole cell-processing device is very small, so we can easily attach the whole device to micro processing instruments. We have developed the special control software with visual feedback control so that each motion could be controlled by a simple mouse click on a PC or joysticks. In experiments, we demonstrated to hold an egg cell whose diameter is 100 mum and inject the pipette whose diameter is 5 mum to the egg cell under the collaboration of these orthogonal micro robots. We have confirmed that this unique micro robotic device has much of potential for actual use to various micro manipulation, such as artificial inseminatation and positioning of miniscule parts of portable devices. The design procedure, basic performance and collaboration with versatile micro robots are also discussed to open the new field for micro-robotics in precision region.

Precise automatic guiding and positioning of micro robots with a fine tool for microscopic operations

This paper describes the unique micro machining system performed by mutiple microrobots. These microrobots, which are composed of piezo elements and electromagnets, can move precisely with the manner of an inchworm on the steel plate. And these robots are equipped with the micro tools such micro drill and micro indentor to provide various micro works with much of flexible layout on the desktop. In this report, two typical applications are to be demonstrated. One of them is that two small robots can collaborate to make thin through-hole of 50 micron under the combination of global and local path control. Here the sample plate attached on the small robot can be positioned precisely to the other robot with micro drill tool, and the relative position between the sample and the tool can be controlled under the local navigation system to get such micro hole. The other application is that the small robot with micro hopping indentor can make array of micro indentation on the sample plate and automatically convey them under the microscope to inspect it

The current progress of measurement standards for vibration in NMIJ/AIST

In this paper, we describe the newly-developed microscopic operation system assisted by one cubic inch sized micro robots under an inverted microscope. These micro robots, which are composed of piezo elements, are capable of moving in any direction, i.e. in X and Y directions as well as precisely rotate at the specified point. And they can convey several surgical fine tools such as a holding pipette and injection pipette so that they can execute flexible operations in a bio-cell while the well-trained operator can conventionally manage this operation. To automate these operations in the bio-cell, the tiny robots can be navigated and positioned by the combination of two styles of coordination measurement. At first as a coarse navigation manner, several micro robots can be guided into the range of the microscope from the arbitrary positions based on the analog signal feedback used by a PSD sensor. And then the microscopic operations can be carried out by monitoring the position of fine tools by analyzing the microscopic images obtained from the CCD camera. The experimental results show that the proposed system succeeds in maneuvering these small robots to provide microscopic operations.

Dynamical analysis and improvement of velocity for a 3 DOF precise inchworm mechanism

This paper outlines the current progress of measurement standards for vibration at the National Metrology Institute of Japan (NMIJ) since 2000. Up to 2000, two accelerometer calibration systems of national standards have established at the NMIJ. These two systems are for the low frequency range (1 Hz to 200 Hz) and for the middle frequency range (20 Hz to 5 kHz). They have been used for national calibration services and their uncertainties have been published on the Appendix C of the CIPM-MRA as the calibration and measurement capabilities (CMCs). Currently, other two systems are under development to extend calibration frequency range. One of the systems is for the very low frequency range (0.1 Hz to 80 Hz). And the other one is for the high frequency range (5 kHz to 10 kHz). The NMIJ is planning to establish these two systems until 2006, and to start the calibration services for 0.1 Hz to 10 kHz together with all 4 systems. Two systems under development are described. Technical features, uncertainty sources of the systems, and the future plan are reported.