Joint Study on Integrated Clinical Analysis System

用微机械加工方法制作了新型常开、常闭微阀和三通微阀。这些微阀结构简单，死体积小，可达几十nl。每个微阀是由一个堆栈型压电致动器驱动和可控的流量范围是从1 ul/min到几十ul/min。这些阀门的通道体积是从16到32 nl。采用三通微阀结构，研制了一种新型的流动注射分析系统中的进样器，并对一种采用被动式单向阀的膜片式高压微泵进行了研究。研制了一种新型单向阀。它有一个简单的结构组成的硅橡胶浮子和通孔。该阀的反向流动阻力约为10大气压min/μ l，在施加的压力为0.5大气压时，正向流动与反向流动之比约为1000。这些值比常规止回阀的值好10至100倍。该阀仅适用于1个大气压以上的高压微泵，并研制了一种新型的微型液体流量传感器。它是一种差压式流量传感器，通过压阻式压力传感器检测节流孔处的压降。该传感器由中心膜片、厚围台面和围膜片组成，中心膜片上开有十字形小孔，厚围梅萨通过厚梁固定在火焰上，围膜片与火焰相连。在支撑梁的端部形成埋入式压敏电阻。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，因此获得了高的压力灵敏度。该传感器的灵敏度约为8 × 1-0 ~（-1）<-5>。埋入式压阻传感器可以消除表面不稳定性，无需任何钝化。

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.