Sharif Digital Repository

Micro grippers are essential tools for manipulation of objects in micron size. An electrostatic micro stepper-motor is used for actuating a proposed gripper mechanism and performance of this gripper is compared with the previous ones. The characteristic of the proposed mechanism is analyzed by simulation and it is shown that the designed gripper has the capability of doing manipulation in micron dimension with an acceptable performance  

Application of robotic instruments in minimally invasive surgery (MIS) has been developing in recent years. The urge to implement biocompatible and less invasive devices found way in use of materials like shape memory alloys. However such designs presented the idea of using heat control actuation in the MIS surgery and some have found noticeable position in robotic surgery. Yet the problems relating to insufficient stroke, slow motion and unfavorable generated heat have to be defeated. In this work it is focused to overcome these problems by a new design. Modern SMA grippers take advantage of two techniques: Net SMA and Spiral SMA. Both of these actuators demand application of high electric... 

Object handling is one of the most important applications of cable-suspended robots, which can be obtained by use of a gripper as its end-effector. In this paper, a novel cable-driven multi-finger gripper assembled on a cable-suspended robot has been presented. Using lock/unlock mechanisms, the under-actuated finger mechanism has been designed to have a human like motion. A cable-suspended robot structure with 3 position degrees of freedom is also proposed by employing active/passive cables in such a way that makes it capable of resisting external moments, while it may be simplified to a spatial point-mass cable robot during positioning operation. Furthermore, the robot workspace has been... 

Abstract: Advancements in microscale technologies have prompted a demand for high precision micro-manipulation. Microgrippers are the primary means of conducting micro-scale operations, and they significantly affect the procedure's performance. This paper presents a novel optimized design for compliant microgrippers, intending to enhance functionality and durability. The mainframe of the proposed microgripper is based on a compact flexure-based compliant structure with four stages of movement amplification. Experiments were designed based on the L25 Taguchi orthogonal arrays. The experiments were conducted using the finite element method in Abaqus 6.14 workbench. Range of motion and maximum... 

Nano-micro grippers are able to pick-transport-place the micro or nanometer -sized materials, such as manipulation of biological cells or DNA molecules in a liquid medium. This paper proposes a novel monolithic nano-micro gripper structure with two axis piezoresistive force sensor which its resolution is under nanoNewton. The results of the study have been obtained by the simulation of the proposed gripper structure in Matlab software. Motion of the gripper arm is produced by a voice coil actuator. The behavior of the cell has been derived using the assumptions in the literatures. Moreover, two simple PID controllers, one for control of the gripper motion and another for control of the force... 

This paper reports the design of an optimal controller to prevent suppressvertical vibration due to undesired out of plane excitations generated by environment or gripper during manipulation for a CMOS-MEMS Nano-Newton capacitive force sensor applied for biomedical applications. Undesired out of plane excitations generated by environment or gripper during manipulation is the most prevalent source of vertical vibration in this type of sensors. To suppress the vibrational movement a PZT 5A is used as actuation mechanism. Discrete element method DEM model and Modal analysis were used to find dominant natural frequencies and mode shape vectors. To eliminate out of plane excitation an optimal...