Joint Study on Integrated Clinical Analysis System

采用微机械加工技术制备了新型常开、常闭微阀和三通微阀，这些微阀结构简单，死体积小，约为数十立方米。每个微阀由堆叠式压电执行器驱动，可控流量范围从1ul /min到几十ul/min。这些阀门的通道容积从16升到32升。采用三通微阀结构，研制了一种新型进样器，是流动进样分析系统中的重要装置。为了制造高压微泵，研究了一种采用被动止回阀的膜片式微泵。研制了一种新型止回阀。它结构简单，由一个硅橡胶浮子和一个通孔组成。在施加压力为0.5 atm时，该阀的逆流阻力约为10 atm min/ul，正逆流比约为1000。这些值比传统的止回阀要好10到100倍。仅限该阀可应用于有效压力至少为1atm的高压微泵。研制了一种新型微型液体流量传感器。它是一种差压式流量传感器，用压阻式压力传感器检测孔口处的压降。该传感器由一个中心膜片组成，在中心膜片上形成一个十字形孔，一个厚实的环绕台面通过一根厚梁固定在火焰上，周围的膜片连接到火焰上。在支撑梁的末端形成埋置的压电电阻。它是由高能离子注入形成的。由于压差引起的应变集中在这一点，因此获得了很高的压力灵敏度。该传感器的灵敏度约为8 × 1-0^<-5>。埋置式压阻式传感器无需钝化即可消除表面不稳定性。

New normally open, normally closed microvalves and a 3-way microvalve have been fabricated by micromachining, These microvalves have a simple structure and small dead volume of the order of tens of nl. Each microvalve is driven by a stack type piezo-actuator and the controllable flow range is from 1 ul/min to tens of ul/min. The channel volume of these valves is from 16 up to 32 nl. A novel sample injector which is an important device in flow injection analysis systems has been developed by applying the 3-way micro valve structure.To fabricate a high pressure micropump, a diaphragm type using passive check valve is studied. A novel check valve is developed. It has a simple structure consists of a silicone rubber float and a through-hole. The reverse flow resistance of this valve was about 10 atm min/ul and the forward to reverse flow ratio was about 1000 at applied pressure of 0.5 atm. These values are 10 to 100 times better than those of the conventional check valves. It is confined that this valve can be applied for a high pressure micropump of available pressure up to at least 1 atm.A new micro liquid flow sensor has been developed. It is a differential pressure type flow sensor which detects the pressure drop at a orifice with a piezoresistive type pressure sensor. The sensor consists of a center diaphragm in which a cross-shaped orifice is formed, a thick surrounding mesa fixed to the flame by a thick beam and surrounding diaphragm connected to the flame. A buried piezo-resistor is formed at the end of the support beam. It was formed by high energy ion implantation. Since the strain caused by differential pressure is concentrated at this point, high pressure sensitivity is obtained. The sensitivity of this sensor is about 8 x 1-0^<-5>. Buried piezoresistive sensor can eliminate the surface instability with out any passivation.