微針陣列(Microneedle array)是利用微機電製程技術使其微小化,能夠穿透皮膚的角質層,又不會刺激到深層組織的神經。文獻研究指出生物可降解性及水溶性高分子微針陣列能完全地在皮膚中溶解,而且無毒,因此使用者完全不必擔心微針斷裂後會永久殘留或是重複使用的衛生安全,也不會有任何醫療廢棄物的產生。 在本研究中,利用符合美國食品藥品監督管理局(Food and Drug Administration,FDA)規範的水溶性高分子材料羧甲基纖維素(Carboxymethylcellulose,CMC),結合微機電製程設備以及翻模技術,成功的製備出高分子微針陣列。高分子微針陣列係利用矽晶片蝕刻出圓柱槽作為模仁材料,再將 SU-8 塗佈於模仁材料上,並藉由製程參數控制,使其成功翻模並製作出深度250μm之微針主結構。再利用 PDMS (Polydimethylsiloxane) 進行二次翻模製作,最後將水溶性高分子材料 CMC注入 PDMS 模具中待固化成型後取出以獲得高分子微針。
Micro Electro Mechanical System fabrication technology(MEMS) has been used to be miniaturization of the microneedle array. The microneedle array can penetrate the stratum corneum of the skin without stimulation to the deep tissue of nerve. The literatures have reported that biodegradable and water-soluble polymer microneedle arrays can be completely dissolved in the skin, and non-toxic. Therefore, users do not have to worry about permanent residual from fracture of microneedle, and unsafety of reuse. There is also not any medical waste generated by using microneedle. In this study, we present the frabrication microneedles of water-soluble polymer, Carboxymethylcellulose(CMC), which is approved to be biocompatible by the Food and Drug Agency(FDA)of the United States. We used micro-electromechanical system and micromold technique to fabricate CMC microneedles. First, microneedle master structure was created using etching technique with controlled process parameters to produce cylindrical array on silicon wafer. SU-8 was then coated on the mold to create the SU-8 master structure of depth 250um. The SU-8 master structure was then coated with polydimethylsiloxane(PDMS)to make PDMS molds for replication. Finally, the PDMS molds were covered with CMC solution. The CMC microneedle can be removed from the PDMS mold after thermal curing.