Mechanically driven microtweezers with integrated microelectrodes

Abstract

This paper presents a method for fabricating a fundamental MEMS tool-microtweezers. Microtweezers offer an attractive option to meet the increasing need to grasp, manipulate and excise microstructures or biological components. The microtweezers presented here augment a standard micromanipulator, allowing precise positioning in three dimensions. An additional micro-drive control knob, which is affixed to the micromanipulator, allows actuation of the tweezer tips through the use of a tether-cable drive system. This drive actuates the tweezer tips by the reciprocating motion of two microfabricated parts: the tweezers and tweezer box. A simple three-layer planar fabrication scheme allows for a broad range of tweezer styles (straight and serrated tips) and sizes (microns to millimeters). For these studies, 20 µm wide and 10 µm thick nickel beams were developed for the tweezer tips, which could endure 20 mN of force. To demonstrate the concept of microassembly, pick and place operations were performed on 10 µm thick film structures. Additional functionality was achieved by integrating platinum-black microelectrodes into parylene-coated tweezers to allow electrophysiological functions such as cellular stimulation and recording. Ultimately, this unique and simple design affords extraordinarily delicate control that is potentially beneficial for applications in microassembly, electrophysiology and microsurgery.

Packaging and characterization of mechanically actuated microtweezers for biomedical applications

“…Given the material composition and mechanics, the longevity of the tool (while not examined here), is also expected to exceed silicon based alternatives [13]. Due to its elegant device design, this system provides a platform in which to integrate additional functionality and sensors [1] that can enhance its already large application space. Characterization of the system shows that prescribed, repeatable actuations and forces can be induced with the microtool tips.…”

“…The packaging system presented in this paper allows previously developed MEMS microtools [1] to be used in a variety of biomedical research applications, potentially replacing crude blunt and dropper type instruments as well as expensive and functionally-limited optical positioning equipment. As these tools provide acuity of control, repeatability, and miniaturization, they can also play a more direct role in experimentation, such as isolating material and tissue samples for chemical and mechanical characterization and manipulation.…”

“…Manuscript Currently, cost and ease of use are major barriers for instruments in this market. Previously developed microtweezers require the use of electrostatic force, electrothermal force, laser power, or shape memory alloy for microtweezer actuation [1][2][3][4][5][6][7][8][9][10][11]. These power and control requirements complicate the microtool fabrication and consequently limit microtool design, size, and material set.…”

Interactive Micromanipulation of Picking and Placement of Nonconductive Microsphere in Scanning Electron Microscope

“…Micro/nano manipulation, fabrication, and assembly techniques have played significant roles in constructing integrated circuits, micro/nano sensors [ 1 , 2 ], and micro electromechanical systems (MEMS) [ 3 , 4 , 5 , 6 ], where manipulation is the most crucial factor [ 7 ]. Integrated MEMS end-effectors, possessing accurate position actuators and force sense feedback, have been widely used in micro/nano manipulation [ 8 , 9 , 10 , 11 ]. Hence, designing proper actuators and sensing units in order to match device functions is required to further explore interactive behaviors, leading to system improvements.…”