流式细胞仪系统中液体变焦透镜的设计与制作

Design and fabrication of the liquid tunable lens in microfluidic cytometer system

以聚二甲基硅烷(PDMS)为基础,设计制作了一种封闭式液体变焦透镜。通过对PDMS薄膜形变情况的仿真分析,利用Matlab数学建模与ANSYS结构仿真,得到薄膜形变结果,确定了合理的透镜腔体结构。在制备工艺上,首先利用SU-8模型制作了PDMS透镜腔,再使用混合PDMS制作出腔体的盖片;然后将两部分进行表面处理后键合,注射填充液、完成二次封装;最后对透镜的表面形变和焦距变化进行了测试,根据测试结果绘制了焦距-磁通量曲线。测试中,在磁通量从200mT到600mT的过程中,焦距由22.0mm变为20.2mm。结果表明,以本文方法制作变焦透镜,可以简化工艺步骤,降低制造成本,减小整体体积,焦距可控,有着更好的密封性,受外界环境干扰小。

The liquid closed tunable lens has been designed and made based on polydimethylsiloxane （PDMS）. The appropriate structure of lens is decided according to mathematical analysis in Matlab soft- ware and structure simulation of PDMS film deformation in ANSYS software. In preparation process, firstly,the chamber of lens is fabricated with an SU-8 mold~ secondly, cover-film is made by using the mixed PDMS,and then two parts of lens are bonding together after surface treatment. After liquid injec- tion and secondary bonding,the whole process was accomplished. Finally, surface deformation and focal distance of the lens are tested with a testing device, and according to the test result, the curve between focal distance and magnetic flux density is plotted. In this process, with the magnetic flux density chan- ging from 200 mT to 600 mT,the focal distance changes from 22.0 mm to 20. 2 mm under the electro- magnetic loads. Results show that fabricating tunable lens with this method can simplify processing se- quence, lower production cost, and reduce the whole structure volume. Moreover, the finished product has controllable focal distance and great sealing property, so the surrounding will have minimal effect on the performance of lens, which may open new possibilities in medical service, optical testing and other fields.