New perspectives for pressure and force sensors thin films combining high gauge factor and low TCR
New perspectives for pressure and force sensors thin films combining high gauge factor and low TCR
复制标题
结合高规格系数和低 TCR 的压力和力传感器薄膜的新视角
作者：
G. Schultes;R. Koppert;Dirk Goettel;Olivia Freitag;A. Probst;U. Werner
可以制备含金属的碳薄膜以表现出压阻特性，对机械应变具有高敏感性并且具有与温度无关的电阻。这种独特的特性组合使这些薄膜适合用于压力、力、重量和扭矩传感器。对于含镍碳膜（通常称为含镍氢化非晶碳，简称 Ni:a-C:H），我们能够证明其应变灵敏度（应变系数）约为 100%。 20 以及在 100 K 至 400 K 的宽温度范围内电阻率温度系数 (TCR) 低于 ±50 ppm/K。因此，与当今传感器中的标准金属薄膜相比，我们薄膜的灵敏度提高了 10 倍。透射电子显微镜 (TEM) 显示，这些薄膜由直径为 10 - 20 nm 的镍晶体纳米团簇组成，仅被石墨烯（或乱层石墨）的几个原子层封装。这些碳封装的团簇嵌入碳基质中。这种新型薄膜被命名为nanoNi@C，即碳封装的纳米镍簇。
Metal containing carbon thin films can be prepared to exhibit piezoresistive properties with a high sensitivity to mechanical strain and with a temperature independent resistance. This unique combination of properties predisposes these films to be used in sensors for pressure, force, weight and torque. For the case of nickel containing carbon films (often termed as Ni containing hydrogenated amorphous carbon, shortly Ni:a-C:H) we are able to demonstrate a strain sensitivity (gauge factor) of approx. 20 together with a temperature coefficient of resistivity (TCR) below ±50 ppm/K in the wide temperature range of 100 K to 400 K. The sensitivity of our films is thus enhanced by a factor of 10 compared with standard metallic thin films in today's sensors. The films consist of crystalline nanoclusters of nickel with a diameter of 10 - 20 nm which are encapsulated by only few atomic layers of graphene (or turbostratic graphite) as revealed by transmission electron microscopy (TEM). These carbon encapsulated clusters are embedded in a matrix of carbon. The new type of films are named nanoNi@C i.e. nano-Nickel clusters encapsulated by carbon.