Micro-solenoid Around A Micro-channel: Its Fabrication And Preliminary Characterization

Magnetic field based Micro-fluidic technology attracts increasing interest among fluid mechanics and machinery, life sciences and other fields, due to its different micro-fluidic capabilities compared with merely electrical or fluid-force controlled device.This article investigated the use of a simple strategy of soft lithography to build the micro-channel surrounded by micro-solenoid unit, and its preliminary characterization.First, based on the preparation of microsolenoid with stainless-steel microwire, microfilament molding processing techniques,it build a diameter of 1 mm circular solenoid around the straight micro-channel, 80μm. The effective length of the solenoid is 15mm in length and thread pitch 0.5mm. The process ends in a circular channel as the liquid exits.Second, the characterization of the device:①Thermal effect, Temperature effect of micro-solenoid based on stainless micro-wire was characterized by combination of temperature measurement devices and dye Rhodamine B. The temperature through the solenoid channel characterization can be drawn in a certain pressure (2.0kp ~ 3.5kp) and current intensity (0 ~ 0.04A) to drive micro-channel micro-droplets, and the temperature inside the micro channel is almost no change. Under a certain velocity, the thermal effects aroused by current on the chip micro-channels are of threshold effects.②evaporation and overcome, micro-droplets within Micro-solenoid around the micro-channels evaporate at room temperature. It characterize the droplets trend in still state and find that the surface characteristics of micro-channel wall is the main factor of droplet stability. When the PDMS channel was coated a layer of phospholipid molecules, the channel micro-droplets are stable, which can reduce the disappearance of volatile liquid droplets problems.③generating the magnetic drive droplet behavior. the surrounding micro-channel micro-solenoid is connected to 3.0V voltage pulse and can be detected with magnetic micro-droplets in the movement of magnetic particles.In this thesis, it analyzed the based of microfilament molding processing technology,and building the micro-channel micro-solenoid device.Particle motion within the device analysis, characterization of the solenoid device thermal effects and electromagnetic effects. The results show that the technique of fabricating micro-solenoid around the micro-channel is simple and feasible. It is worthy of further characterization of some key parameters and has potential applications.