Metallic microgripper with SU-8 adaptor as end-effectors for heterogeneous micro/nano assembly applications

Abstract

This paper presents design, fabrication, and characterization of easy-to-handle electroplated nickel microgrippers with SU-8 adaptors for heterogeneous micro/nano assembly applications. Two distinctive designs of microgrippers as end-effectors of micro/nano assembly applications have been developed in this work. The first design is 200 lm thick electroplated nickel microgripper with a plastic mechanical displacement amplifier that is driven by a piezoelectric actuator. The piezoelectric actuator is capable of creating $5 lm displacement which is amplified to $10 lm by the plastic mechanical amplifier and finally such displacement generates 50-139 lm microgripper tip displacement. The second design is 20 lm thick electroplated nickel microgripper embedded in SU-8 adaptor for easy-to-handle operation. The second design is electro-thermally actuated using a set of jouleheated bent beams. With applied actuation voltage in the range of 2-4 V, the microgripper generates tip displacement of 4-32 lm. Extensive thermal and mechanical finite element modeling have been carried out and measurement results were compared with the simulation results. Such developed easy-to-handle microgrippers can be used for micro/nano pick-and-place assembly applications.

Theoretical and Experimental Studies of Bending of Inorganic Electronic Materials on Plastic Substrates

“…Equations 1, 5 and 11 give the interfacial shear strength t c ¼ 20.8 MPa, where the elastic properties of the film, adhesive layer and substrate are E f ¼ 130 GPa, n f ¼ 0.27, E a ¼ 4.4 GPa, n a ¼ 0.44, E s ¼ 4.0 GPa, and n s ¼ 0.44. [27,28] Similarly, the interface delamination and film fracture occur when the maximum interfacial tensile (peeling) stress in Equation 7 and tensile stress in the film in Equation 10 reach the tensile strengths s c of the interface and s c Si of the silicon film, respectively, i.e.,…”

A sub-micron metallic electrothermal gripper

“…Among them, electrothermal actuation is a good candidate for microgrippers with controllable precision and reliability owing to their large displacements and moderate gripping force at low actuation voltage. The electrothermal microgrippers have been investigated in various materials such as highly doped silicon (Que et al 2001), poly-Si (Lai et al 2004), and metals (Que et al 2001;Enikov and Lazarov 2003;Kim et al 2004). Because of the relatively large thermal expansion coefficients of metals, metallic electrothermal grippers could be actuated at lower actuation voltages for larger displacement with lower steady-state power consumption over silicon or poly-silicon electrothermal microgrippers (Enikov and Lazarov 2003).…”

“…A variety of materials including polycrystalline silicon (poly-Si) (Kim et al 1992;Millet et al 2004) and metals (Carrozza et al 1998) have been used as structural materials in the fabrication of microgrippers using microelectromechanical systems (MEMS) technologies such as surface micromachining, bulk micromachining, and the LIGA techniques. The typical actuation principles of microgrippers are electrostatic (Kim et al 1992;Millet et al 2004), piezoelectric (Carrozza et al 1998), and electrothermal (Que et al 2001;Lai et al 2004;Enikov and Lazarov 2003;Kim et al 2004) actuations. Among them, electrothermal actuation is a good candidate for microgrippers with controllable precision and reliability owing to their large displacements and moderate gripping force at low actuation voltage.…”

Development of piezoelectric actuator based compliant micro gripper for robotic peg-in-hole assembly

“…A dynamic model of the piezoelectric unimorphs is developed. Kim et al [12] have focused on metallic micro gripper with SU-8 adaptor as end-effectors for heterogeneous micro/nano assembly applications. Lan et al [13] have focused on optimization of compliant gripper for macro/micro manipulation using nonlinear constrained optimization technique to analyze contact problems of compliant gripper.…”