本研究使用胺基化氧化石墨烯製作可撓式濕度感測元件，胺基化氧化石墨烯是由氧化石墨烯與兩種二胺反應而得，兩種二胺分別為乙二胺(Ethylenediamine,EA)和己二胺(1,6-hexanediamine,HA)。
此可撓式濕度感測器擁有工作範圍大(20-90% RH)、高感度、反應/恢復時間短(52 s、72 s)、對溫度依賴性低(-0.4% RH/℃)與長期穩定性佳(200 days)等優點。同時利用阻抗頻譜分析圖來探討濕度感測器的傳導機制，由阻抗頻譜分析的結果可知在低濕狀態下為電子傳導機制，在高濕狀態下為離子傳導為主。
Novel impedance-type humidity sensors were made using diamines-functionalized graphene oxide (GO) films coated on alumina or plastic substrates. Ethylenediamine (EA) and 1,6-hexanediamine (HA) were used to functionalize GO using N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) (EDC/NHS) as the coupling reagent. The effect of the chain lengths of diamine on the electrical and humidity-sensing properties of the diamine-functionalized GO film was investigated. The diamine-functionalized GO film was characterized by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). The impedance-type humidity sensor that was made of EA-GO film exhibited a wide range of working humidities, a high sensitivity, an acceptable linearity, a small hysteresis, high flexibility, a short response/recovery time, a weak dependence on temperature and high long-term stability. The humidity sensor’s linearity depended on the applied frequency. Complex impedance plots and activation energy were applied to elucidate how the ions (H3O+) dominate the conductance of the diamine-functionalized GO film.
