On-demand microdroplet generation method based on hybrid actuation of pneumatic and electrohydrodynamics

Abstract

The invention discloses an on-demand micro-droplet generation method based on the hybrid drive of pneumatic and electrohydrodynamics. The device for realizing the method is supplied by a high-pressure air source, and the pressure regulating valve is used to control the air pressure at the front end of the high-speed electromagnetic valve, which is controlled by a single-chip microcomputer. High-speed solenoid valve opening time. After the high-pressure gas enters the liquid storage chamber, it produces Helmholtz oscillation, which is stable after several cycles of attenuation. Industrial cameras and LED lights are used to monitor the droplet generation process and assist in the regulation of the system. Refer to the air pressure waveform detected by the air pressure sensor, and adjust the high-speed solenoid valve and pressure regulating valve reasonably. By adjusting the high-speed solenoid valve and the pressure regulating valve to control the air pressure waveform, the volume and shape of the trace liquid that is squeezed out of the nozzle can be adjusted, thereby regulating the size of the micro-droplet. Compared with the high-voltage pulse power supply micro-droplet generating device, the cost of the present invention is greatly reduced.

Description

technical field [0001] The invention relates to a micro-droplet generation device driven by a mixture of pneumatic and electrohydrodynamics, and realizes the control technology of generating micro-droplets on demand and adjusting its size by adjusting the opening time, air pressure and voltage level of the electromagnetic valve in the device , mainly used in the application of micro-liquid samples, and can be used in printing electronics, drug development, biomedical material printing and other fields. Background technique [0002] As conventional inkjet printing technologies, including piezo-actuated jetting and thermal bubble-actuated jetting, have expanded to other reference areas, more unconventional inkjet printing technologies have also made great progress. These unconventional injection methods mainly include pneumatically driven injection, electrohydrodynamic (EHD) injection, etc. They are used in a wide range of fields including biomedical printing. Among them, th...

AI Technical Summary

Problems solved by technology

However, EHD micro-droplet ejection technology also needs to face many difficulties

Since the liquid generation is affected by the continuous electric field force and the flow rate of the liquid supply system, although the frequency of droplet generation is controlled by voltage, it is difficult to maintain stability, and it is impossible to achieve on-demand injection

Using a high-voltage pulse power supply can overcome the above-mentioned problem of unstable injection frequency to a certain extent, but on-demand injection is still difficult to achieve

At the same time, the price of high-voltage pulse power supply is much higher than that of high-voltage constant voltage power supply, which greatly increases the system cost

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