降低驅動電壓於可應用於光機電系統之離子高分子金屬複合材料之可靠性研究

Abstract

離子聚合物金屬複合材料為一種電制動高分子，對電氣刺激有極高的響應，由於其具有驅動電壓低和體積小等優點而被作為制動器應用於許多光機電系統。當施予電壓時，離子聚合物金屬複合材料會因為內部離子遷移而被制動，故離子液體會影響離子聚合物金屬複合材料的物理性質。在本文中我們使用了非水溶液的離子液體來取代水溶液型離子聚合物金屬複合材料並探討其可靠性。傳統鉑電極離子聚合物金屬複合材料配合氫氧化理水溶液可以達到最大位移量，但制動過程容易造成水的電解，為了改善電解問題來延長在空氣中的操作壽命，須選擇高電解電壓且低蒸氣壓的離子液體。此外，利用聚對二甲苯封裝也可以防止溶劑的散失。使用銀來取代傳統鉑電極可製作出可在低於電解電壓下驅動的離子聚合物金屬複合材料。本文主要探討離子聚合物金屬複合材料在空氣中的耐用度，經由聚對二甲苯封裝並配合高電解電壓離子溶液，銀電極離子聚合物金屬複合材料在空氣中的使用壽命為沒有封裝的水溶液型銀電極離子聚合物金屬複合材料的15倍，但最後仍然無法制動，我們發現影響離子聚合物金屬複合材料在空氣中可靠性的主要因子為電極的龜裂。鉑電極和銀電極離子聚合物金屬複合材料的制動位移量和反應時間也會在本文中比較。

IPMC (Ionic Polymer Metallic Composite) is a kind of electroactive polymer (EAP) which is capable of exhibiting large property changes in response to electrical stimulation. IPMC is used as an actuator in opto-mechanical application because of its low driving voltage and small size. The mechanism of IPMC actuator is due to the ionic diffusion when the voltage gradient is applied, so that the type of ionic solution has a large impact on the physical properties of IPMC. In this paper, the reliability tests of IPMC with non-aqueous ionic solution are demonstrated. Pt-IPMC with LiOH aqueous solution exhibits the best maximum displacement, but the water in LiOH solution is electrolyzed because of the low electrolysis voltage 1.23 V of water. To improve electrolysis problems and the operation time in the air, proper solvents including high electrolysis voltage and low vapor pressure should be chosen. Parylene-coated IPMC module can also prevent IPMC from solvent loss. Traditional platinum electrodes are replaced by silver to decrease surface resistance which can be operated below the electrolysis voltage. The reliability tests focus on the durability of IPMC in dry air. The improvements of IPMC fabrication such as Ag-IPMC can be further developed in this paper. Through using parylene protection and ionic solution which has high electrolysis voltage, the life time of Ag-IPMC surviving in dry air is up to 15 times greater than uncoated Ag-IPMC with aqueous solution but IPMC still cannot survive in the air. We mentioned the possible problems for IPMC in actuation and found that the crack of electrodes has the main impact on the reliability of IPMC. The comparison of response time and tip bending displacement of Pt-IPMC and Ag-IPMC will also be presented.