Characterization of an electro-thermal micro gripper and tip sharpening using FIB technique

Abstract

A micromachined electro-thermal gripper, first introduced by Ivanova et al. (Microelectron Eng 83:1393-1395, represents a promising candidate for the manipulation and handling of micro or even nano-scaled objects. To further optimize the performance of the device, a detailed electrical and mechanical characterization is needed. Due to the so-called duo-action gripper approach (i.e., a separate actuator for closing and opening action) these investigations focused on the maximum (minimum) opening width being 11.5 lm (3.3 lm), while in rest position a value of 4 lm is feasible. The maximum, electrical input power is limited to 80 mW/actuator element, resulting in a current density of up to 1.27 MA cm -2 in the corresponding metal layers. When applying, however, larger current densities the probability of device failure increases substantially as in combination with an enhanced temperature of about 200°C electromigration effects occur in the metallization. Furthermore, the cut-off frequency and parasitic effects during actuation such as the z-deflection and the increase in length of each arm both showing values of up to 3 lm have been investigated as a function of operation parameters. Finally, the tips of the gripper were sharpened using Focused Ion Beam technique to a radius of less than 1 lm for gripping operations in space-restricted environments or for the manipulation or handling of sub-lm scaled objects.

Review of Electrothermal Actuators and Applications

“…Some of the structures were fabricated in the PolyMUMPs (Multi-User MEMS Process) method, a foundry process using several polysilicon structural layers; • Three-beam actuator: An example and analysis of a microgripper with two hot arms were presented in [39,40]. The microgripper design has improved performance for manipulation tasks; various enhancements were presented, such as tip sharpening [41] and duo-actuation regime [42]; • Folded heater: A novel design that eliminates parasitic heating in the cold arm was proposed in [35]. The dielectric structural material (SU-8) allowed incorporation of the whole heater structure in one arm only, as illustrated in Figure 2a; • Meander heater: In the work of [43], a meander-shape metallic heater was embedded in the wide arm (hot arm) of the polymer microgripper.…”

The Nonlinear Dynamic Behaviors of Electrostatic Micro-Tweezers

“…These studies developed to show the feasibility of micro robots and biological science. Recently, the electro thermal micro gripper was attracted to some investigations [18,19].…”

Design and Application of a Novel In Situ Nano-Manipulation Stage for Transmission Electron Microscopy

“…Commercial micro-grippers are available from companies such as Femto Tools (Zurich, Switzerland), Kleindiek Nanotechnik (Reutlingen, Germany), Klocke Nanotechnik (Aachen, Germany), and Zyvex Instruments (Richardson, TX, USA). However, the majority of these gripping systems are designed for grasping objects of a few tens of microns to a few hundreds of microns (Goldfarb & Celanovic, 1999; Carrozza et al, 2000; Menciassi et al, 2003; Roch et al, 2003; Nguyen et al, 2004; Choi et al, 2005; Clevy et al, 2005; Fahlbusch et al, 2005; Kim et al, 2005; Perez et al, 2005; Huang et al, 2006; Nah & Zhong, 2007; Solano & Wood, 2007; Kim et al, 2008; Kyung et al, 2008; Panepucci & Martinez, 2008; Chen et al, 2009; Zubir et al, 2009; Deutschinger et al, 2010; Jayaram & Joshi, 2010; Raghavendra et al, 2010), with some grippers for sub-micron objects (Boggild et al, 2001; Nakayama, 2002; Jericho et al, 2004; Molhave & Hansen, 2005; Blideran et al, 2006 a , 2006 b ; Sardan et al, 2008; Andersen et al, 2009). Most of the gripping systems that operate in the micron range were designed and developed for SEM-level experiments.…”