Sains Malaysiana 40(3)(2011): 275–281

Piezoelectric Micropump with Nanoliter Per Minute Flow for Drug Delivery Systems

(Pam Mikro Piezoelekrik dengan Aliran Nanoliter Seminit untuk Sistem Penghantaran Bendalir Ubat)

Juliana Johari, Jumril Yunas, Azrul Azlan Hamzah & Burhanuddin Yeop Majlis*

Institute of Microengineering and Nanoelectronics (IMEN)

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor D.E., Malaysia

Diserahkan: 15 Mei 2010 / Diterima: 3 September 2010

ABSTRACT

A Piezoelectric Actuated Valveless Micropump (PAVM) has been designed and successfully fabricated using MEMS fabrication processes. The micropump uses a PZT: Pb(ZrTi)O_x ceramic plate to actuate a silicon membrane which bends when a voltage is applied to the piezoelectric actuator. The resultant reciprocating movement of the pump membrane is then converted into pumping effect. By integrating dynamic passive valves into the device, the pump would then operate continuously with volumetric pumping rate determined by the frequency of the driving voltage. Simulation work to determine the micropump fluidic characteristics was performed using CoventorWare MemFSI™ module. The pump was fabricated on a double side polished silicon wafer via simple two-mask micromachining process. The fabricated micropump, having an outer dimension of 14 mm × 14 mm × 2 mm, was then tested with DI (deionized) water as the test liquid. A driving voltage of 16 Vpp was applied to the PZT actuator. Pump rate of 4.98 nL per min was obtained at 0.673 kHz. The fabricated micropump envisages a promising pumping method to be implemented into drug delivery systems.

Keywords: CoventorWare MemFSI; drug delivery; MEMS; PAVM; piezoelectric micropump

ABSTRAK

Pam mikro Janaan Piezoelektrik Tanpa Injap (PAVM) telah direka bentuk dan berjaya difabrikasi melalui proses fabrikasi MEMS. Pam mikro ini menggunakan plat seramik PZT: Pb(ZrTi)O_x untuk menggerakkan membran silikon yang membengkok bila voltan dikenakan pada penggerak piezoelektrik. Pergerakan salingan yang terhasil pada membran pam kemudiannya diterjemahkan kepada kesan pengepaman. Dengan mengintegrasikan injap-injap pasif dinamik kepada peranti, pam ini boleh beroperasi tanpa henti dengan kadar pengepaman ditentukan oleh frekuensi voltan pemacu. Analisis simulasi untuk menetukan ciri-ciri aliran pam mikro tersebut telah dilakukan dengan menggunakan modul MemFSI™ CoventorWare. Pam tersebut kemudiannya difabrikasi di atas wafer silikon dengan kedua-dua permukaan licin melalui proses pemesinan mikro dwi-topeng mudah. Pam mikro tersebut, yang bersaiz 14 mm × 14 mm × 2 mm, kemudiannya diuji menggunakan air ternyah ion sebagai cecair uji. Voltan pemacu 16 Vpp telah dikenakan pada penggerak PZT. Kadar pengepaman 4.98 nL seminit telah dicapai pada 0.673 kHz. Pam mikro ini mencetus satu kaedah pengepaman yang berpotensi digunapakai dalam sistem penghantaran bendalir ubat.

Kata kunci: CoventorWare MemFSI; MEMS; pam mikro piezoelektrik; PAVM; penghantaran bendalir ubat

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*Pengarang untuk surat-menyurat; email: burhan@vlsi.eng.ukm.my