基于柔性材料的热式MEMS医用输液流量传感器的研发

Research and development of thermal MEMS medical infusion flow sensor based on flexible materials

提出了一种新型的基于柔性基底的用于测量输液速度的热式微机电系统(MEMS)流量传感器。传感器由树脂打印的外壳、柔性元件以及外部电路组成。应用热损失原理,通过控制电路使发热镍(Ni)线恒温工作,通过测温Ni线检测发热Ni线上游的温度变化来反映输液流速。首先,对传感器进行了仿真验证,确定传感器关键参数。使用光刻、磁控溅射等技术在聚酰亚胺(PI)基底上加工Ni线并在表面镀了一层派瑞林来进行防水处理。传感器核心元件尺寸为1 cm×2 cm,封装后的尺寸为6 cm×2 cm。使用不同温度的生理盐水对传感器进行了标定,在热源温度50℃时,其精度可达5 mL/h,量程可达300 mL/h,满足日常输液使用。

A novel thermal MEMS flow sensor based on flexible substrate for measuring flow rate of infusion system is presented.This sensor consists of resin-printed shell,flexible components,and external circuits.It adopts the principle of heat loss,makes the heating nickel wire work at a constant temperature through the control circuit,and derives the corresponding flow value by detecting temperature change through the temperature measuring nickel wire of upstream of the heating nickel wire.Firstly,the sensor is simulated and verified,and the key parameters of the sensor are determined.Photolithography,magnetron sputtering and other technologies are used to process nickel wire on polyimide(PI)substrate and a layer of parylene on the surface is plated for waterproofing.The core element size of sensor is 1 cm×2 cm,and the packaged size is 6 cm×2 cm.The sensor is calibrated with different temperature of normal saline.When the heat source temperature is 50℃,its precision can reach 5 mL/h,and the range can reach 300 mL/h,which can meet the usage of daily infusion.