A hybrid Electrostatic-piezoelectric integrative actuated microsystem for robot-assisted laser phonomicrosurgery.

International audienceSeveral forms of microactuators have been investigated for microrobots, for example, electrothermal actuators [1,2], electrostatic actuators [3], piezoelectric actuators [4], electromagnetic actuators [5], acoustic actuators, pneumatics actuators, and shape memory alloys. Key enable technology for these miniaturized actuators is microfabrication processes for microelectromechanical systems because the processes can create submicron features with high precision, mass productive, and low cost. Examples of fabricated systems have been developed and some medical applications have been reported [1-5]. This talk provides literature reviews to compare advantages and disadvantages of micro actuators for biomedical applications. Then, we propose a new device that is devoted to medical applications (laser phonomicrosurgery) within the European μRALP-project [6]. Based on precise micromachined electrostatic and piezoelectric actuators, the platform is assembled using micro assembly approach. With sizes less than 5mm x 5mm x 5mm, the proposed design has three degree-of-freedom: two rotational motions around the in-plane axis and one out-of-plane translational motion. Static and dynamic analysis of the device is simulated by Finite Element Analysis and compared to theoretical calculations. Fig. 1 depicts the CAD-scheme of the designed device. This system preserves outstanding characteristics of both actuators for fast response and low power consumption. Moreover, challenge of electrostatic actuator for a high driving voltage and challenges of piezoelectric actuator for hysteresis effects and charge leakage problems are reduced with collaborated controls and operations of two sets of actuators

Characterizations and Micro-assembly of Electrostatic Actuators for 3-DOF Micromanipulators in Laser Phonomicrosurgery.

International audienceThis paper presents a design of electrostatic actuators for 3-DOF micromanipulators in robot-assisted laser phonomicrosurgery. By integrating three sets of electrostatic actuators in a vertical configuration, scanning micro-mirror canbe used as a manipulator for laser source. Key enable technology for these miniaturized actuators is microfabrication processes for microelectromechanical systems (MEMS) because the processes can create submicron features with high precision, mass productive, and low cost. Based on precise micromachined electrostatic actuators, the platform is assembled using micro assembly approach. With sizes less than 5 mm x 5 mm x 5 mm, the proposed design has three degree-of-freedom: two rotational motions around the in-plane axis and one out-of-plane translational motion. Static and dynamic analysis of the device is simulated by Finite Element Analysis (FEA) and compared to theoretical calculations. This system preserves outstanding characteristics of electrostatic actuators for fast response and low power consumption. By micro-assembly of the scanning micromirror, the endoscopic systems can be created with a high range of motion and high scanning speed. The target applications of this system include laryngeal microsurgery, optical coherence tomography (OCT), and minimally invasive surgeries (MIS)

Micro fuel cell and nanoscale colloidal separation systems: design, fabrication, and characterization

This thesis presents different types of membranes fabricated by microfabrication processes for applications on micro fuel cell, proton exchange membrane, and removal process of nanoscale colloids. First, the development of a millimeter-scale fuel cell with on-board fuel is enabled by implementing a passive control mechanism and porous silicon for residual filtration. The regulating membrane can control a delivery of water into a chamber of chemical hydride by the internal pressure in the hydride chamber. Consequently, the generated hydrogen exits to the Nafion-based Membrane Electrode Assembly (MEA) through the porous silicon membrane at the bottom of the hydride chamber. Within a total volume of 9 μL, which makes it the smallest fully integrated fuel cell reported in the literature, these devices deliver an energy density of ~250 Wh/L. Tentative applications for this device are microelectronics, microsystems, and micro robots. Another membrane development in this study is a silicon-based Proton Exchange Membrane (PEM) with self-assembly molecules. After anodization processes of a 20 μm thick silicon membrane in a hydrofluoric (HF) solution, techniques for self-assembly of molecules with sulfonate (SO3H) functional groups within extremely high aspect ratio silicon nanopores are examined. The set up was used to continuously extract solvent to functionalize a porous membrane with pore sizes of ~5-10 nm. The assembled molecule is 3-mercaptopropyl-trimethoxysilane (MPTMS). Then, the thiol end group of the MPTMS molecule was subsequently oxidized to sulfonate group to enhance proton transport through the pores. Penetration of the MPTMS molecules down to the bottom of the pores was verified through characterizing the membrane thickness by using Time of Flight-Secondary Ion Mass Spectroscopy (ToF-SIMS) and X-ray Photoemission Spectroscopy (XPS), as well as the water desorption isotherm technique. These porous silicon membranes can influence developments of proton exchange membrane, self-assembled layer deposition, and micro fuel cells. Last, the possibility of Electrokinetics-based device with alternating current (AC) traveling waveform membrane is validated for the applications of water purification and colloidal removal. The development of the membrane is simulated by engineering software. The membrane is nanostructured with embedded electrodes that are connected with different spatial phase of AC voltage supplies. The testing of fabricated membranes shows a concentration of colloids with ~25% removal efficiency of 93 nm fluorescent latex colloids across the membrane. With a possibility of pumping particles into another chamber, this traveling wave membrane can be an alternative for a colloidal separation in microfluidic systems

Scanning Micromirror Platform Based on MEMS Technology for Medical Application

This topical review discusses recent development and trends on scanning micromirrors for biomedical applications. This also includes a biomedical micro robot for precise manipulations in a limited volume. The characteristics of medical scanning micromirror are explained in general with the fundamental of microelectromechanical systems (MEMS) for fabrication processes. Along with the explanations of mechanism and design, the principle of actuation are provided for general readers. In this review, several testing methodology and examples are described based on many types of actuators, such as, electrothermal actuators, electrostatic actuators, electromagnetic actuators, pneumatic actuators, and shape memory alloy. Moreover, this review provides description of the key fabrication processes and common materials in order to be a basic guideline for selecting micro-actuators. With recent developments on scanning micromirrors, performances of biomedical application are enhanced for higher resolution, high accuracy, and high dexterity. With further developments on integrations and control schemes, MEMS-based scanning micromirrors would be able to achieve a better performance for medical applications due to small size, ease in microfabrication, mass production, high scanning speed, low power consumption, mechanical stable, and integration compatibility

Scanning Micromirror Platform Based on MEMS Technology for Medical Application

This topical review discusses recent development and trends on scanning micromirrors for biomedical applications. This also includes a biomedical micro robot for precise manipulations in a limited volume. The characteristics of medical scanning micromirror are explained in general with the fundamental of microelectromechanical systems (MEMS) for fabrication processes. Along with the explanations of mechanism and design, the principle of actuation are provided for general readers. In this review, several testing methodology and examples are described based on many types of actuators, such as, electrothermal actuators, electrostatic actuators, electromagnetic actuators, pneumatic actuators, and shape memory alloy. Moreover, this review provides description of the key fabrication processes and common materials in order to be a basic guideline for selecting micro-actuators. With recent developments on scanning micromirrors, performances of biomedical application are enhanced for higher resolution, high accuracy, and high dexterity. With further developments on integrations and control schemes, MEMS-based scanning micromirrors would be able to achieve a better performance for medical applications due to small size, ease in microfabrication, mass production, high scanning speed, low power consumption, mechanical stable, and integration compatibility

Design and Simulation of XZ MEMS Micropositioning with 3D-Complex Structure

International audienceMicropositioning systems are widely used in many applications, for example, optical industry, medical devices, and micro-assembly applications. Commonly, MEMS-based micropositioning systems use conventional fabrication techniques such as lithography, etching, and thin-film processes. However, a typical microfabrication process by using the masking and etching operations is limited to fabricate a 3-dimensional complex device. This research presents a novel design of a 3D micropositioning system with electrostatic comb drives with a converting mechanism. The device can convert the in-plane motion to the out-of-plane displacement. The proposed model is possible by using FEMTOPRINT ® machine which combines material modification by femtosecond laser-beam and chemical wet etching. The results from the simulation shown that the 3Dcomplex micropositioning system can achieve a wide range of workspace up to 1,212.79 μm 2 . In X-axis and Z-axis, it can translate up to a maximum displacement of 33.34 μm and 75.14 μm respectively, while the footprint of the device is 1.65×1.10 mm 2 . This device can be a new prototype of MEMS based-micropositioning system named “glassy MEMS” that is suitable for a 3D-complex mechanism and can be used in many applications

Structural Analysis and Static Responses of Electrostatic Actuators for 3-DOF Micromanipulators in Phonomicrosurgery.

International audienceWhile the searching for electrostatic actuators with large displacements is going on, this paper will demonstrate the parameters that influence the performances of linear electrostatic actuators. A comparison of theoretical calculations and experimental results for linear electrostatic actuators will also be presented for phonomicro-surgery. Theoretically, transverse displacement of electrostatic comb drive depends on supplied voltage, pull-in voltage, and length of spring suspension. In this study, two types of spring suspension (single beams and double-folded beams) are studied for different behaviors of linear electrostatic actuators. Normally, the folded-beam are implemented with the guilded-axis along at the center. There are still contradictions about the deflection of the single beam suspension and the folded-beam. Engineers and scientists predicted the deformations for their own designs. Some results show that the single beam can provide higher deformation, while the other reported the result for both design are relevant or higher. Calculations of stiffness and allowable transverse displacement are also compared to the simulation results among different types. The calculations are used for designing the performances of electrostatic actuators with a fit-curve for different parameters. Then, the experimental results indicate characteristics of linear electrostatic actuators for different suspension designs and different parameters. Next, these electrostatic actuators will be implemented for a 3-DOF (tip-tilt-piston) micro-mirror in phonomicrosurgery by using a micro-assembly approach with marker and assembly block to place three electrostatic comb-drives in the precise position. With this development, MEMS-based micro-mirror designs can enhance capability of biomedical apparatus that require high speed, low power consumption, and high reliability

Scanning Micromirror Platform Based on MEMS Technology for Medical Application.

International audienceThis topical review discusses recent development and trends on scanning micromirrors for biomedical applications. This also includes a biomedical micro robot for precise manipulations in a limited volume. The characteristics of medical scanning micromirror are explained in general with the fundamental of microelectromechanical systems (MEMS) for fabrication processes. Along with the explanations of mechanism and design, the principle of actuation are provided for general readers. In this review, several testing methodology and examples are described based on many types of actuators, such as, electrothermal actuators, electrostatic actuators, electromagnetic actuators, pneumatic actuators, and shape memory alloy. Moreover, this review provides description of the key fabrication processes and common materials in order to be a basic guideline for selecting micro-actuators. With recent developments on scanning micromirrors, performances of biomedical application are enhanced for higher resolution, high accuracy, and high dexterity. With further developments on integrations and control schemes, MEMS-based scanning micromirrors would be able to achieve a better performance for medical applications due to small size, ease in microfabrication, mass production, high scanning speed, low power consumption, mechanical stable, and integration compatibility

SQUIPABOT: a Mesoscale Parallel Robot for a Laser Phonosurgery.

International audienceThis paper presents the design of a mesoscale robot for laser phonosurgery. The proposed design is situated between conventional mechanism and MEMS technology.A combination of compliant structures and innovative micromotors enables to achieve two decoupled tilting angle, a high range (up to 45°) and a precise positioning of a laser beam. The design methodology and the optimization of the compliant structure are detailed. Preliminary results and tests are described which have induced promising performances of the mesoscale robot for laser steering