二氧化錫參雜對聚苯胺/聚二氧乙基噻吩聚苯乙烯磺酸 二氧化碳感測器的影響

Abstract

隨著科技的演進以及物聯網(IoT) 的崛起，市場對於低製作成本以及低功耗的感測器的需求也有所成長，但市面上大多數氣體感測器為金屬氧化物或是光學式的，兩種感測器都不符合這兩個需求。另一方面有機聚合物的氣體感測器擁有較低的製造成本、較低的操作溫度以及低功耗，正好符合物聯網感測器的條件。但是它們致命的缺點為相對短壽命以及穩定性不良。為了克服壽命上的限制，我們在聚苯胺(Emeraldine Base-Polyaniline) 以及聚二氧乙基噻吩聚苯乙烯磺酸(Poly(3,4-ethylenedioxythiophene)polystyrene sulfonate) 混合而成的材料中加入了二氧化錫。並且針對新的混和材料測試二氧化碳的反應、壽命測試等相關實驗，並做進一步的討論。綜合來講參雜二氧化錫並沒有成功延長感測器使用壽命，但是參雜0.025% 二氧化錫的感測器相較於無參雜的感測器對二氧化碳有較好的反應量，例如說於濃度20000 pppm 時，0.025% 二氧化錫的反應量為20.6%，無參雜的感測器反應量只有18.9%。在應用層方面參雜二氧化席的感測器靈敏度，也代表著可以量測到氣體濃度更微小的變化。

With the rise of Internet of Things (IoT), the demand for low-cost and low power consuming sensors has increased, currently most commercial gas sensors are made of metal oxides or detect gases via optical methods, however they do not meet the 2 key requirements, low cost and low power consumption, essential for an IoT sensor. On the other hand organic polymer gas sensors have the advantages of relative lower manufacturing costs, lower operating temperatures usually around room temperature, hence low power consumption in comparison with other types of gas sensors. However they have the disadvantage of having a short lifetime, and poor stability. In trying to overcome the problem of short lifetime, EB-PANI and PEDOT:PSS CO₂ gas sensor is doped with tin oxide. The new nanocomposite sensor is then tested for response against CO₂, lifetime tests and other related experiments. Overall results show that doping our organic polymer did not achieve our goal of prolonging sensor lifetime, however the sensitivity of the 0.025% doped sensor towards CO₂ is higher, 20.6% at 10000 ppm, than the non-doped sensor, 18.9% at 10000 ppm. A higher sensitivity means that our sensor now is able to register the signal response change, for a smaller change in gas concentration.