膜片式微型F-P腔光纤压力传感器

Diaphragm based miniature fiber optic pressure sensor with F-P cavity

为满足工业和生物医学领域对微型化传感器的需求,实验研究了基于Fabry-Perot(F-P)干涉仪原理的膜片式微型光纤压力传感器的制作工艺。在单模光纤端面上直接熔接外径约175μm的毛细石英管,在石英管的另一端制作敏感膜片,从而使光纤端面与膜片内表面之间形成F-P干涉腔。采用电弧熔接、切割、腐蚀膜片等方法制作了石英膜片式压力传感器,该传感器在0～3.1MPa内F-P腔的腔长变化灵敏度为41.09nm/MPa,压强测量分辨率为681Pa,并具有很小的温度敏感系数。在30～140℃,温度交差敏感<1.07kPa/℃。为了克服石英膜片减薄困难的缺点,选用聚合物材料(PSQ)作为压力敏感膜片制作了F-P传感器。室温下在0.1～2.1MPa,PSQ膜片的F-P腔长变化灵敏度达到1886.85nm/MPa,压强测量分辨率达到53Pa,十分接近人类或其他动物的体内压强测量水平。

In order to meet the requirements of both industry and biomedicine for miniature pressure sensors,the miniature fiber optic pressure sensors based on Fabry-Perot （F-P） interferometric principle are manufactured. A piece of hollow fiber with a 175μm outer diameter is fused directly onto a fi ber tip and a thin diaphragm is fused onto the other end of the hollow fiber, then the F-P cavity is formed between the fiber tip and the diaphragm. An miniature entire quartz fiber optic pressure sensor is fabricated by cleaving, fused splicing and etching. The pressure response of the sensor is tested, test results show that the cavity pressure sensitivity is 41.09 nm/MPa in the full pressure scale of 0-3.1 MPa,and the pressure resolution is 681 Pa. The temperature sensitivity of the sensor has also been tested under atmospheric pressure, and a weak temperature dependence of 1.07 kPa/℃ is obtained in the test temperature from 20 ℃ to 140℃. Since it is hard to further decrease the thickness of the quartzose diaphragm, a polymer（PSQ） diaphragm is used as a pressure diaphragm to increase the sensitivity of the sensor. The pressure response of the PSQ diaphragm based sensor has also been tested under room temperature, it shows the cavity pressure sensitivity is 1 886.85 nm/MPa in the full pressure scale of 0. 1-2. 1 MPa, and the pressure resolution is 53 Pa. These results are very closed to the resolution of the pressure measurement in human being and animals.