Design of a Novel MEMS Microgripper with Rotatory Electrostatic Comb-Drive Actuators for Biomedical Applications

Abstract

Primary tumors of patients can release circulating tumor cells (CTCs) to flow inside of their blood. The CTCs have different mechanical properties in comparison with red and white blood cells, and their detection may be employed to study the efficiency of medical treatments against cancer. We present the design of a novel MEMS microgripper with rotatory electrostatic comb-drive actuators for mechanical properties characterization of cells. The microgripper has a compact structural configuration of four polysilicon layers and a simple performance that control the opening and closing displacements of the microgripper tips. The microgripper has a mobile arm, a fixed arm, two different actuators and two serpentine springs, which are designed based on the SUMMiT V surface micromachining process from Sandia National Laboratories. The proposed microgripper operates at its first rotational resonant frequency and its mobile arm has a controlled displacement of 40 µm at both opening and closing directions using dc and ac bias voltages. Analytical models are developed to predict the stiffness, damping forces and first torsional resonant frequency of the microgripper. In addition, finite element method (FEM) models are obtained to estimate the mechanical behavior of the microgripper. The results of the analytical models agree very well respect to FEM simulations. The microgripper has a first rotational resonant frequency of 463.8 Hz without gripped cell and it can operate up to with maximum dc and ac voltages of 23.4 V and 129.2 V, respectively. Based on the results of the analytical and FEM models about the performance of the proposed microgripper, it could be used as a dispositive for mechanical properties characterization of circulating tumor cells (CTCs).

Curvature Dependent Electrostatic Field in the Deformable MEMS Device: Stability and Optimal Control

“…The scientific community, in the MEMS field, is busy on two main fronts. The first one, theoretically oriented, is devoted to the analysis and synthesis of physical-mathematical models [11] of problems, such as coupled thermal-elastic systems [9,11,12], electrostatic-elastic systems [11,13,14], magnetically actuated systems, and microfluidics [11,[15][16][17][18]; the second front is actively engaged in technology transfer in various application areas, such as the production of MEMS for biomedical applications (miniaturized bio-sensors, tissue engineering, and so on) [14,19]. Clearly, there is no lack of lines of research that combine the theoretical approach with technology transfer [1,11].…”

Design and Validation of a Single-SOI-Wafer 4-DOF Crawling Microgripper

“…MEMS-based microgrippers, equipped with rotary comb-drive actuators, have been presented to characterize the mechanical properties of cells [12,13,14]. Further applications of microgrippers could consists of in vitro simulation of basic surgical operations, by testing and analyzing the microgripper–tissue interactions.…”

Dual-Stimuli Responsive Carbon Nanotube Sponge-PDMS Amphibious Actuator

“…Actuators, which can move in response to input energies [1][2][3], have had increasing attention paid to them over the years for different applications such as biomedical devices [4,5], soft robots [6,7] and artificial muscles [8,9]. Various smart materials have been utilized for actuation to meet different demands, such as the shape memory polymer (SMP) [10][11][12], shape memory alloy [13][14][15][16][17] shape memory hydrogels [18][19][20][21][22] and ionic electroactive polymer(including ionic polymer-metal composites, conductive polymer and polyelectrolyte [23][24][25]) to realize the flexibility, large actuation displacement and high actuation force properties [26][27][28][29].…”