Cell micro-injection device and robust impedance control method thereof

Abstract

The invention discloses a cell micro-injection device which comprises a connecting rod, a packaging device connected with the connecting rod, a piezoelectric actuator fixed in the packaging device, a micro-injection needle, an injector and a hub type compliant mechanism, and the two ends of the injector are connected with the packaging device and the hub type compliant mechanism respectively, the micro-injection needle is fixedly connected with the hub type compliant mechanism; the hub type compliant mechanism is provided with a reed type compliant unit used for transmitting axial vibration to the microinjection needle. According to the micro-injection device, the transverse vibration of the needle head in the micro-injection device can be reduced, and the damage to cells in the cell puncture process is reduced.

Description

technical field [0001] The invention relates to the technical field of precision control and the field of biomedical engineering, in particular to a cell microinjection device and a robust impedance control method thereof. Background technique [0002] Microinjection technology is a technology that manipulates a micromanipulator to control a microinjection needle to manipulate cells or early embryos under a high-power inverted microscope. It is widely used in drug development, in vitro fertilization, biological cloning, transgenic and other fields. The core of microinjection technology is to puncture cells or early embryos with high efficiency and low damage. Due to the low success rate and low efficiency of manual puncture, the puncture process began to develop towards automation. Automatic puncture technology widely uses piezoelectric actuators to drive microinjection needles to complete the puncture process. However, studies have shown that the piezoelectric signal can ...

AI Technical Summary

Problems solved by technology

[0004] (1) Fatigue problem: Fatigue problem is a major cause of failure of the compliant mechanism, especially for the compliant guide mechanism that adopts a high-frequency vibration strategy for puncturing.

The inherent stress concentration problem of concentrated compliant mechanism is more likely to cause fatigue failure of the mechanism

[0005] (2) Stiffness problem: The lateral vibration of the compliant mechanism depends on the lateral stiffness in principle, and the plane mechanism can only increase the stiffness perpendicular to the plane direction by increasing the thickness, which will lead to the coupling of stiffness in all directions, and cannot make the compliant mechanism Achieving an ideal stiffness ratio

[0006] (3) Parasitic motion problem: the circumferential asymmetry of the planar mechanism cannot eliminate the circumferential coupling error caused by the input, resulting in the generation of lateral parasitic motion, and the reduction of mechanical efficiency and transmission accuracy

The existing force and position control applied to cell puncture needs to switch between two different control laws, which may lead to instability of the entire system, which in turn leads to long convergence time and cannot be performed under high-frequency vibrations. Force and position following control; disturbances such as hysteresis and friction of the piezoelectric actuator also pose great challenges to the existing force and position control. These external disturbances greatly increase the steady-state force error and steady-state position error

Therefore, the existing force and position control system has the disadvantages of long convergence time, instability, and large steady-state error, and cannot be well applied to cell puncture, especially the high-frequency vibration puncture, which is more promising at present.

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