Papers by Keyword: Micro-Gripper

Abstract: A development of a novel electro thermal micro-gripper for handling of Head Gimbal Assembly (HGA) is an ultimate goal of this study. The scope of this study covers a design, fabrication and performance evaluation of the electro thermal micro-gripper. ANSYS software was used to examine the magnitude of tip displacement, exerting force and induced stress to investigate the mechanism’s viability for handling of HGA. Electroplating of nickel was employed to construct the micro-gripper’s mechanisms with three different sizes, and their displacement and exerting force were then examined. From the experiments, each mechanism deflected between 100 to 220 μm while the exerting force was over 200 mN at 25 ^oC above room temperature. Therefore, the results suggested that the new electro thermal micro-grippers are viable for the HGA handling application.

Abstract: In this paper, a kind of micro-gripper is introduced using vacuum adsorption method. The gripper is used to grasp a mm size micro-part in a micro-assembly process. Because of the requirement of the adsorption force, the negative pressure control system is employed which can let the micro-gripper inhale and exhale freely. Accordingly, the adsorption force of the micro-gripper can be controlled accurately. The PLC controller is used to get the pressure information from the electronic proportional valve. The PID control law is employed to adjust the opening of the valve. In this way, the micro-gripper can easily clamping and release micro-part especially for some micro-parts with adsorption effect. Experiments show that the adsorption force on the micro-part is greater than 0.5N satisfying the requirement of the clamp to grasp the micro-part.

Abstract: Based on the requirements of that the finger can move in parallel, and the displacement of the finger can be detected, the micro-gripper driven by piezoelectric actuator is designed based on the displacement amplification structure with the flexure hinge. The static analysis, the modal analysis, the harmonic response analysis and the transient response analysis of the micro-gripper are carried out by using the finite element analysis software ANSYS. The results of the finite element analysis show that the finger is fully able to move in parallel, and can detect the displacement of the finger; the maximum displacement of the finger is about 101 μm, the first natural frequency is about 130 Hz; the finger tip displacement under the 1 μm step input is about 20 μm, the fingertip vibration is about ±2 μm.

Abstract: Micro-gripper is a key module in IC/LED wire bonding. The paper presents a micro-gripper combining with piezoelectric material and flexible structure. The dynamic and static characteristics of the micro-gripper are calculated by finite element method, and the natural frequencies, the vibration modes, as well as the deflection range of the micro-gripper are obtained. In the experiment, the high-speed camera was used to track the vibration of the micro-gripper, and the relationship between deflection range and driven voltage was established. The vibration behavior was measured by a non-contact laser measuring device. These results can help improve the reliability of the micro-gripper used in wire bonding.

Abstract: In nano manipulation, carbon nanotubes (CNT) mounted on the AFM tip was used for pick and place of the nano size objects. In releasing step, the van der Waals adhesive force among the object and the contact surfaces of the gripper is not still well understood. In this paper, the adhesive electrostatic force, van der Waals (VDW) force between two cantilever tips and VDW force among cantilevers and the object are considered as dominant forces to pick and place the nano object. The equations governed on nanotweezer are solved using FEM code. The effect of object size, gap size and tips length on pull-in voltage are evaluated. The presented model could be used to design the tweezers for pick and place of size-defined nano object mounted on microgripper.

Abstract: Considering assembly and disassembly of micro-gripper, connection and isolation of lead, a new micro-gripper based on piezoelectric bimorphs is designed by using finite element analysis. First, a detailed structure of the micro-gripper is designed based on piezoelectric bimorph cantilevered beams. Second, static and dynamic characteristics of the micro-gripper are analyzed by piezoelectric coupling field analysis technique of ANSYS. For the static performance, there is a linear relationship between displacement and driving voltage of the micro-gripper. The maximum displacement of the micro-gripper finger is about 81.9 μm under the maximum driving voltage 200 V. For dynamic performance, the natural frequency and the response time of the gripper is about 45 Hz and 1.1 ms, respectively. The micro-gripper could meet the designed needs.

Abstract: The current developed micro-grippers are not effectively used in micro-assembly within the scale of 0.01-10mm due to some practical problems. In this paper, we present a novel integrated micro-gripping system. In this system, the vac-sorb gripper and the micro-gripper based on a linear motion stage are employed together to stably pick up miniature mechanical structures in different shapes and dimensions. The gripping force is detected in real time and used as a feedback to control the action of the system. The design of the system and the implementation of the feedback mechanism are described in details. Experiments are taken and analyzed and the results show the designed functionality of the system.

Abstract: This paper presents a hybrid type of microelectromechanical systems (MEMS) microgripper integrated with an electrostatic mechanism and vacuum technology. Vacuum tools are integrated in this microgripper in order to achieve a reliable and accurate manipulation of microobjects. The microgripper is fabricated by a surface and bulk micromachining technology. The pick and release micromanipulation of microobjects is accomplished by electrostatic driving force caused by comb structure and an auxiliary air pressure force from air pump. The performance of this new hybrid type of microgripper is experimentally demonstrated through the manipulation of 100–200μm polystyrene balls. Experimental results show that this microgripper can successfully fulfill the pick and release micromanipulation.

Abstract: This work is focused on design and fabrication of a hybrid-type electrostatic silicon microgripper integrated vacuum tool. Vacuum tools are integrated in this novel microgripper in order to improve its pick and place capability. Surface and bulk micromachining technology is employed to fabricate the microgripper from single crystal silicon wafer (i.e., no silicon on insulator wafer is used). And the bonding technology is used to form the gas pipes for the vacuum tool. The linear motion of the microactuator is converted into a rotational gripping motion by a system of spring beams. At a driving voltage of 80V, a deflection of 25μm at the arm tip of the gripper is achieved.

Abstract: In this work, we present the characterisation of an electrothermally actuated microgripper that operates in both dry and liquid media, and shows improved performance versus existing devices. The microgripper, fabricated in a combination of polymeric (SU8) and conductive materials (Au), is able to produce displacements up to 110 μm in air and 30 μm in liquid. In both cases, the voltage and the electrical power required is minimal (less than 3 V and 180 mW respectively) and so both, high temperatures and electrolysis, are prevented. Micromanipulation experiments have successfully demonstrated the gripping, holding and transport of mice oocytes (approx. diameter 100 μm) in a biological media.