The zona pellucida (ZP) micro-dissection technology has played a key role in the field of artificial assisted reproduction (such as ZP thinning, preimplantation genetic diagnosis (PGD), etc.). Currently, laser ZP micro-cutting technology using far-infrared beam has the disadvantages of high price, thermal damage, and low degree of freedom. Piezoelectric ultrasonic micro-cutting technology has matured at the biological tissue level, but ultrasonic cutting at the single-cell level is still difficult to achieve. In this paper, based on piezoelectric ultrasonic tissue micro-cutting theory, the mechanism of ultrasonic cutting of the oocyte ZP was researched, and a cutting method for the ZP was proposed. Based on the design formula of flexure's stiffness, this paper analyzes the effects of dimension parameters on the vibration condition of micro-needle. An ultrasonic cell surgery instrument based on a three-dimensional stereoscopic flexure-guided structure was designed. The modal analysis and the harmonic response analysis of the structure were performed using finite element software. The experimental results show that the lateral amplitude of the newly designed device's needle tip is smaller than the traditional one in the specified range of frequency. Among them, when the operating frequency is around 22.1 kHz, the lateral amplitude of the needle tip is reduced to 0.021μm. Finally, the theoretical method of piezoelectric ultrasonic cutting on single cell layer is presented for the first time, which has a broad prospect and significance for artificial assisted reproduction.

Camera can sensor the environment on the lane by extracting the lane lines, but such detection is limited to a short distance with effect of illumination and other factors; radar can detect objects a long distance away but cannot detect the lane conditions. This paper combined machine vision with millimeter-wave radar and extracted the nearby distinct lane line through images; at the same time, the radar obtained the motion trajectory information of distant vehicles, then the least-square method was used to make curve fitting on those motion trajectory information in order to reconstruct the lane line information. Finally, in the stage of fusing two segments of lane lines, the goodness of fit was applied to complete the matching of corresponding lane lines. While, for areas between two segments of lane lines that neither camera or radar can detect, we established a lane model, utilized probabilistic neural network to select the corresponding lane model for matching, and then used approximate mathematics expression according to the selected lane model, thus obtaining the final front road information of current vehicle.

In the die bonding process of MEMS microphone chip, the exact center and rotate angle of MEMS microphone chip is corrected after the vacuum nozzle has adsorbed it. In order to achieve high speed and precision placement function, the flying vision system based on rotating mirror is proposed, the mirror is driven to rotate by the power drawn from the nozzle rise and fall movement through a rack and pinion mechanism, the nozzle pick and place functions is not interfered by mirror through designing the rack and pinion mechanism parameters. The vision system can capture an static clear MEMS chip image when the mirror rotated to a 45 degrees position referenced with horizontal position, the center position and rotating angle of MEMS chip is fast calculated by the fine and coarse Hough Transform Algorithm, the center location and angle will be corrected by the control system during the mounted head is flying to placement position. The experimental results show that the system can obtain high-quality MEMS microphone chip image, the chip's center position and rotating angle correction algorithm takes no more than 0.1s, so it can meet the high-speed placement requirements. In this proposed flying vision system, mechanical structure is simple and compact, MEMS chip's image is clear without distortion, and there is no restriction on the mounted head movement trajectory. The flying vision system significantly enhances the quality and efficiency of SMD Chip; it can be widely used in the surface mounted system.

Due to scale effects, the releasing of micro objects has been a long-standing challenge in micromanipulation applications. In this paper a micromanipulation system is presented based on the adhesion control with compound vibration. This adhesion control technique employs inertia force to overcome adhesion force achieving 100% repeatability with releasing accuracy of 4±0.5μm, which was experimentally quantified through the manipulation of 20-100μm polystyrene spheres under an optical microscope. The micromanipulation system consists of a microgripper and a piezoelectric ceramics module. The compound vibration comes from the electrostatic actuator and the piezoelectrically driven actuator. Surface and bulk micromachining technology is employed to fabricate the microgripper used in the system from a single crystal silicon wafer. Experimental results confirmed that this adhesion control technique is independent of substrate. Theoretical analyses were conducted to understand the releasing mechanism. Based on this preliminary study, the micromanipulation system proves to be an effective solution for active releasing of micromanipulation.

The liquid dosing system has been studied widely as it had been used in many technical and medical applications. And in recent years, the miniaturization of the liquid dosing system as well as the accuracy of liquid transfer has gradually become a hot research field. In this paper, a MEMS (Micro-electromechanical system) flow sensor was integrated with a PZT(Piezoelectric Transducer) pump to make a closed-loop drug dosing system. Benefiting from the feedback of sensor information, the system can self-adjust the driving voltage of the PZT pump to precisely dispensing desired liquid volume. First, the structure and principle of the PZT pump will be introduced briefly. Secondly, the MEMS flow sensor is presented. Finally, the fuzzy PID (Proportional-Integral-Differential) closed-loop control strategy is proposed to calculate and adjust the driving voltage in real-time. Finally, experiment results show that the drug delivery system could precisely delivery drug volume with error smaller than 0.01µL when desired volume is 100µL.

This paper presents the design, fabrication, and application of an piezoelectrically driven microgripper integrated sidewall piezoresistive force sensor for measuring the gripping force. Surface and bulk micromachining technology is employed to fabricate end-effectors and sensor of the microgripper from a single crystal silicon wafer. Vertical sidewall surface piezoresistor etching technique is used to form the side direction sensors. The end-effectors of the gripper are four-bar structures. Two fixed cantilever beams integrated with piezoresistive sensor are designed to sense the gripping force, and a piezoelectrically driven microactuator is designed to provide the force to operate the other two movable bars. The piezoelectrically driver adhered with the silicon end-effectors generates a linear horizontal motion 9 mum, which is amplified to 30 mum at the bar tip of the microgripper. Then the range of the operation is 25 mum - 140 mum. Testing results verify that the vertical sidewall surface piezoresistor etching technique is effective. The sensitivity of the piezoresistive sensors is better than 72 V/N, and the resolution is better than 3 muN.

In biomedical areas, such as protein crystallization, drug discovery and medical diagnostics, thousands of reagents with different viscosities need to be transferred or dispensed in submicroliter range. Most of the commercial automated liquid dispensing systems need to be calibrated through experiment to accurately dispense liquids when the reagents viscosities change, which is time consuming and less accurate. In this paper, an intelligent precise liquid handling system was developed, in which a high speed MEMS flow sensor was used. Benefiting from the feedback of sensor information, the system can self-adjust the open time of the solenoid vale to accurately dispensing desired reagent volume without pre-calibration. Firstly, the system construction was introduced in detail. Secondly, a novel closed-loop control strategy was proposed to calculate valve open-time for each dispensing cycle, which makes the system immune to liquid viscosity, pressure fluctuation and some other disturbances. Finally, experiments results are presented with different dispensing volumes, coefficient of variance (CV) has been shown to be below 3% at 1ldquol and approach 4% at 100 nl.

Microscopic computer vision differs significantly from macroscale computer vision. Autofocusing techniques is of fundamental importance to automated micromanipulation in providing high level task understanding, task planning and real time control. Depth-from-Focus (DFF) based autofocusing method is widely used in many microscope systems, while the low efficiency limited its application in micromanipulation system which needs fast autofocus for real time control. In this paper, Depth-From-Defocus (DFD) algorithms are proposed to improve autofocusing performance and robustness for microscopic optics. Two different schemes based on look-up table and function relation are investigated and evaluated through actual experiments. Experimental results validate the performances of the two proposed autofocusing methods.

Batch microassembly of MEMS sensors is limited by the manual manipulation required specially trained technicians. To reduce the production costs and simultaneously obtain high production quality, a flexible microassembly system for automated bonding of MEMS sensors is developed. The system consists of a set of autonomous modules that can adapt their structures and functions to various sizes of MEMS sensors, including positioning stages, a microscopy imaging system, a flexible micromanipulator, a heater, a fixture, a supply station and auxiliary systems. Optomechatronic design is essential to the development of integrated systems due to the basic importance of microscope optics to microassembly. In this paper, major methodology issues in optomechatronic design of this system are introduced. A wavelet-based microscopic focus measure and a control scheme with a modified Smith predicator to decrease the inherent time delay of vision system are presented. A smart force sensor with one dimension is employed to sense and control the interactive force. To perform manipulations automatically, a control system, including a task planning level and a real-time execution level, is developed. The productivity of the flexible microassembly system is validated by further experiments

This paper presents a Task-reconfigurable system developed for efficient and reliable MEMS assembly. The system consists of a set of autonomous modules that can adapt their shape and function to various assembly tasks, including a distributed 6 DOF coarse positioning module, a distributed 5 DOF fine positioning module, grippers designed for different manipulation tasks with same mechanical interface, a multi-view imaging system, and control software. In order to achieve high precision and dexterity in microassembly, a hybrid vision-force control method is proposed. For easier reconfiguration, a semi-automated calibration method is applied to quick calibrating of the new reconfigurations. Analysis and 3 cases of microassembly are presented to demonstrate that this system has high reconfigurability and adaptability.

This paper presents the automatic microassembly of miniaturized gear system by hybrid vision-force control with the vision system and the 3-DOF force sensor feedback data. The assembly process consists of three phases, including visual positioning, searching meshing state, and inserting. Visual feedback is used to achieve the coarse positioning and guide the grasping and transporting of microparts during the visual positioning phase. During the searching phase, a fuzzy PID controller is used to control the contact force on z axis and fuzzy logic strategy is developed to search the meshing state by the force feedback on x and y axes. The tolerance compensations movement is used to support the inserting task to avoid the case of blocking and prevent the micro parts from damaging. The assembly experiment of three planetary gears validates the hybrid force control strategy.