Romero Francisco J, Rivadeneyra Almudena, Becherer Markus, Morales Diego P, Rodríguez Noel
Pervasive Electronics Advanced Research Laboratory, University of Granada, 18071 Granada, Spain.
Department of Electronics and Computer Technology, University of Granada, 18071 Granada, Spain.
Micromachines (Basel). 2020 Jan 29;11(2):148. doi: 10.3390/mi11020148.
In this paper, we present a simple, fast, and cost-effective method for the large-scale fabrication of high-sensitivity humidity sensors on flexible substrates. These sensors consist of a micro screen-printed capacitive structure upon which a sensitive layer is deposited. We studied two different structures and three different sensing materials by modifying the concentration of poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS) in a graphene oxide (GO) solution. The results show that the aggregation of the PEDOT:PSS to the GO can modify its electrical properties, boosting the performance of the capacitive sensors in terms of both resistive losses and sensitivity to relative humidity (RH) changes. Thus, in an area less than 30 mm, the GO/PEDOT:PSS-based sensors can achieve a sensitivity much higher (1.22 nF/%RH at 1 kHz) than other similar sensors presented in the literature which, together with their good thermal stability, time response, and performance over bending, demonstrates that the manufacturing approach described in this work paves the way for the mass production of flexible humidity sensors in an inexpensive way.
在本文中，我们提出了一种简单、快速且经济高效的方法，用于在柔性基板上大规模制造高灵敏度湿度传感器。这些传感器由微丝网印刷电容结构组成，在该结构上沉积有敏感层。我们通过改变氧化石墨烯（GO）溶液中聚（3,4 - 乙撑二氧噻吩）/聚苯乙烯磺酸盐（PEDOT:PSS）的浓度，研究了两种不同结构和三种不同传感材料。结果表明，PEDOT:PSS在GO上的聚集可改变其电学性能，在电阻损耗和对相对湿度（RH）变化的灵敏度方面提高了电容式传感器的性能。因此，在小于30平方毫米的面积内，基于GO/PEDOT:PSS的传感器能够实现比文献中报道的其他类似传感器高得多的灵敏度（在1 kHz时为1.22 nF/%RH），再加上其良好的热稳定性、时间响应以及弯曲性能，表明本文所述的制造方法为以低成本大规模生产柔性湿度传感器铺平了道路。
