We develop a novel humidity sensor by wrapping the spider dragline silk (SDS) on a tapered single-mode fiber (TSMF) to configure a multimode interference (MMI) structure and obtain the optical spectrum. The TSMF is fabricated by heating a single-mode fiber (SMF) while applying tension. SDS is employed as humidity-sensing material, thus the SDS wrapped on the TSMF enable TSMF structure to be sensitive to the changes of environmental relative humidity (RH). SDS refractive index changes with the change of environmental RH, which causes the shift of multimode (MMI) interference spectrum. Experimental results indicate that the average sensitivity of the proposed SDS-based sensor is 0.532 nm/%RH in the range of 30 %RH–89 %RH and the maximum sensitivity is 0.789 nm/ %RH in the range of 70 %RH-89 %RH. The humidity-sensing curve is approximately fitted by the linear method. The response time is 374.46 ms. We provide a new method for the fabrication of natural protein-based environmental friendly sensor.

我们通过将蜘蛛拉铲丝（SDS）包裹在锥形单模光纤（TSMF）上，以配置多模干涉（MMI）结构并获得光谱，从而开发出一种新型的湿度传感器。通过在施加张力的同时加热单模光纤（SMF）来制造TSMF。SDS被用作湿度传感材料，因此包裹在TSMF上的SDS使TSMF结构对环境相对湿度（RH）的变化敏感。SDS折射率随环境RH的变化而变化，从而引起多模（MMI）干扰光谱的移动。实验结果表明，建议的基于SDS的传感器的平均灵敏度在30％RH–89％RH的范围内为0.532 nm /％RH，最大灵敏度在70％RH-89的范围内为0.789 nm /％RH ％RH。湿度感应曲线通过线性方法近似拟合。响应时间为374.46 ms。我们为基于天然蛋白质的环保传感器的制造提供了一种新方法。