Electronic control of elastomeric microfluidic circuits with shape memory actuators
Electronic control of elastomeric microfluidic circuits with shape memory actuators
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DOI：
10.1039/b804515a
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发表时间：
2008-09-01
期刊：
影响因子：
6.1
通讯作者：
Scherer, Axel
中科院分区：
文献类型：
--
作者：
Vyawahare, Saurabh;Sitaula, Suresh;Scherer, Axel
最近，通过使用多层软光刻来模制弹性体，已经构建了具有数百个独立阀门的复杂流体回路。然而，微流体电路的这种缩小并没有与控制电路的驱动和接口元件的相应小型化相匹配；虽然流体回路很小（类似于 10-100 微米宽的通道），但 Medusa 的头状接口（由外部气动螺线管和控制每个独立阀门的管道或机械销组成）要大一到四个数量级（类似于毫米到厘米）。因此，在微流体中使用大规模集成来实现便携式、高通量应用的梦想受到了阻碍。通过将多层软光刻与形状记忆合金 (SMA) 相结合，我们展示了组装在印刷电路板 (PCB) 上的电子激活微流体组件，例如阀门、泵、锁存器和多路复用器。因此，高密度电子控制微流体芯片可以与标准光电元件一起集成在 PCB 上。此外，我们引入了微流体状态的概念，它是阀门状态的组合，类似于集成电路（IC）微处理器的指令集。微流体状态可以用硬件或软件来表示，我们提出了一种控制架构，可以使外部控制线呈对数减少。这些进展使我们更接近于构建在物理上和抽象模型上都类似于电子 IC 的微流体电路。
Recently, sophisticated fluidic circuits with hundreds of independent valves have been built by using multi-layer soft-lithography to mold elastomers. However, this shrinking of microfluidic circuits has not been matched by a corresponding miniaturization of the actuation and interfacing elements that control the circuits; while the fluidic circuits are small (similar to 10-100 micron wide channels), the Medusa's head-like interface, consisting of external pneumatic solenoids and tubing or mechanical pins to control each independent valve, is larger by one to four orders of magnitude (similar to mm to cm). Consequently, the dream of using large scale integration in microfluidics for portable, high throughput applications has been stymied. By combining multi-layer soft-lithography with shape memory alloys (SMA), we demonstrate electronically activated microfluidic components such as valves, pumps, latches and multiplexers, that are assembled on printed circuit boards (PCBs). Thus, high density, electronically controlled microfluidic chips can be integrated alongside standard opto-electronic components on a PCB. Furthermore, we introduce the idea of microfluidic states, which are combinations of valve states, and analogous to instruction sets of integrated circuit (IC) microprocessors. Microfluidic states may be represented in hardware or software, and we propose a control architecture that results in logarithmic reduction of external control lines. These developments bring us closer to building microfluidic circuits that resemble electronic ICs both physically, as well as in their abstract model.