- 學位論文
以指叉式電極為基礎製作高分子濕度感測器及其於環境及人體肌膚濕度之應用
A Polymer Humidity Sensor Based on Interdigital Electrodes for Environmental Humidity and Human Skin Moisture Applications
摘要
濕度感測器已有多年之研究，對於自動化之發展、民生品質之提升及環境品質的應用範疇，感測器之使用有其必要性，濕度感測器ㄧ般多用於環境監測及控測上，市面常見之用途如家庭用電子式溫濕度計、除濕機、恆濕器等。然而不僅係空氣中含有水分，一般生物體中亦含有水分含量，尤其近年來生物科技之發展，美容產業因此蓬勃，對於肌膚水分含量之檢測格外重要，因此若能將濕度感測器之先前技術應用於肌膚濕度量測上，朝醫學美容方面發展，係相當可行且值得研究之方向。 一般而言可略分為電容型式與阻抗型式二大類，本論文係利用印刷電路板製作指叉式電極為基礎，並以熱壓合之方式固定聚醯亞胺薄膜於電極之上，研製一具雙感測功能之電容式感測器，其可偵測環境相對濕度及皮膚角質層水分含量之感測器，並討論指叉電極形狀對於感測器基礎電容及感測特性之影響，分別找出適合環境量測與肌膚量測之指叉電極。 此環境濕度及皮膚濕度感測器之基礎原理係採電容方式進行感測，因所覆蓋感測膜之電極間會感應電場，產生電容效應，因水分子之介電常數約為80左右，當電場路徑中有水分子進入，則會因水分子而造成整體介電常數之上升，進而產生造成輸出電容之上升，水分愈多，電容變化愈劇烈，因此可藉由電容變化之多寡推得水分含量之多寡。 於環境監測上，本研究所製作之聚醯亞胺電容式濕度感測器適用的量測範圍介於50%R.H.至95%R.H.間；於皮膚角質層濕度量測上，可針對一般型及濕潤型肌膚進行量測，於肌膚濕度量測之同時，亦可利用聚醯亞胺電容式濕度感測器進行室內濕度之監控，以確保肌膚濕度量測之準確性。 本濕度感測器之特點係使用雙面印刷電路板技術進行指叉電極及外部導線連接區之製作，將外部導線連接區與感測區分別製作於印刷電路板之二側，可保持感測區域之平坦性，減少肌膚濕度量測時接觸面積不均勻所造成之誤差，並以熱壓合之方式固定聚醯亞胺覆蓋膜，可與皮膚直接次接觸而不造成脫落，重覆利用性佳，製作方式簡易，成本亦相對低廉。
並列摘要
Humidity sensors have been investigated for many years. In general, the humidity sensors are applied in environmental detection and control. For household electric appliances, there are hygrometers, dehumifying dryer, humidity controlled chamber and so on. However, an interesting issue is that not only the air but also any creature hold the water within. Nowadays bioengineering applications develop soon and dermatocosmetic research follows to develop. The detection of water content of the skin reveals significance for skin diagnostic. Hence, it is valuable and feasible to investigate skin moisture sensors based on structure of the humidity sensors. According to the output form, there are two types of humidity sensors in common. One is resistive type and another is capacitance type. In this thesis, a capacitive-type humidity sensor based on interdigital capacitance (IDC) that fabricated by printed circuit board (PCB) covering a polyimide film that is realized by hot press method is described. The moisture-sensitive device has two functions. One is for environmental humidity detection and another is for diagnosing the water content of the stratum corneum. For electrode pattern, the relationship between the geometric configurations of the IDC and the sensing properties of the moisture sensor are also discussed. Moreover, the optimum geometry of moisture-sensitive IDCs for environmental humidity and human skin moisture detection are confirmed. For environmental humidity detection, the linear range of the polyimide capacitive humidity sensor is from 50%R.H. to 95%R.H. For skin moisture detection, the sensor can determine different moisture conditions of the human skin (dry, normal, and hydrated skin). In addition, when the skin moisture measurements are carried out, the humidity sensor can work at the same time to confirm the environmental condition to reduce the error caused by environmental humidity interference. This thesis provides a PCB technique to fabricate the IDC and offer an easy bonding technology for soldering. The interconnection method between front and back electron pathway can keep the active sensing area flat to reduce the error of the skin moisture detection. The sensor based on polyimide film that is covered by hot press method can directly contact with the human skin and can be reused. Furthermore, the advantages of the humidity sensor are its easy fabrication process, low cost, and capable for mass production.