Microfluidic Optical Shutter Flexibly - Actuated via Electrowetting-on-Dielectrics with
Microfluidic Optical Shutter Flexibly - Actuated via Electrowetting-on-Dielectrics with
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DOI：
10.1155/2017/7610652
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发表时间：
2017-12
期刊：
影响因子：
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通讯作者：
H. Fouckhardt;J. Strassner;Carina Heisel;Dominic Palm;Christoph Doering
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文献类型：
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作者：
H. Fouckhardt;J. Strassner;Carina Heisel;Dominic Palm;Christoph Doering
可调显微光学涉及的设备，其光学特性可以改变在操作过程中没有机械移动固体部分。通常液滴被驱动，因此可调微光学与微流体密切相关。一种这样的设备/模块/单元类型是光学快门，其移入或移出光路。在我们的例子中，传输部分包括一个移动的透明和导电的水滴，嵌入在不导电的变黑的油中，也就是说，在流体内250 μm长的光路上，在570 nm波长处具有30 dB衰减的不透明乳液（在可见光谱范围内平均为15 dB）。在“打开快门”状态下，单元的插入损耗为1.5 dB。该致动是通过具有1 kHz的V峰到峰的矩形AC电压脉冲的电润湿（EWOD）来实现的。为了灵活地允许竖直x-y平面中的水平、垂直和对角液滴移动，接触结构被制备成使得存在四个可能的静止液滴位置。该单元被配置为串联的两个电容器（沿着轴），使得EWOD力以<20 ms的响应时间对称地作用在60 nl液滴的前部和后部。
Tunable microoptics deals with devices of which the optical properties can be changed during operation without mechanically moving solid parts. Often a droplet is actuated instead, and thus tunable microoptics is closely related to microfluidics. One such device/module/cell type is an optical shutter, which is moved in or out of the path of the light. In our case the transmitting part comprises a moving transparent and electrically conductive water droplet, embedded in a nonconductive blackened oil, that is, an opaque emulsion with attenuation of 30 dB at 570 nm wavelength over the 250 μm long light path inside the fluid (15 dB averaged over the visible spectral range). The insertion loss of the cell is 1.5 dB in the “open shutter” state. The actuation is achieved via electrowetting-on-dielectrics (EWOD) with rectangular AC voltage pulses of V peak-to-peak at 1 kHz. To flexibly allow for horizontal, vertical, and diagonal droplet movement in the upright x-y plane, the contact structures are prepared such that four possible stationary droplet positions exist. The cell is configured as two capacitors in series (along the axis), such that EWOD forces act symmetrically in the front and back of the 60 nl droplet with a response time of <20 ms.