Proceedings of the ASME 2009 Micro/Nanoscale Heat and Mass Transfer International Conference MNHMT2009 December 18-21, 2009, Shanghai, China MNHMT2009-18516 INHALED PULMONARY DRUG DELIVERY PLATFORM USING SURFACE ACOUSTIC WAVE ATOMIZATION Aisha Qi, James R. Friend, Leslie Y. Yeo Micro/Nanophysics Research Laboratory Mechanical and Aerospace Engineering Monash University Clayton, Vic, Australia 3800 Email: aisha.qi@eng.monash.edu.au ABSTRACT Atomization has been widely applied in pulmonary drug de- livery as a promising technology to transport drug formulations directly to the respiratory tract in the form of inhaled particles or droplets. Because of the targeted treatment, the drug can be delivered directly to the site of inflammation, thus the need for systemic exposure and the possibility of side effects are both re- duced. Therefore pulmonary drug delivery has significant ad- vantages over other methods in the treatment of respiratory dis- eases such as asthma. The most common atomization methods employed in pulmonary drug delivery are jet atomization and ultrasonic atomization. However, the difficulty is in producing monodispersed particles/droplets in a size range of 1–5 micron meter in diameter, necessary for deposition in the targeted lung area or lower respiratory airways, within a controllable fashion. In this paper, we demonstrate surface acoustic wave (SAW) at- omization as an efficient technique to generate monodispersed aerosol to produce the required size distribution. The SAW atom- izer is made of a 127.86 Y-X rotated single-crystal lithium nio- bate piezoelectric substrate, which is patterned with chromium- aluminum interdigital transducer (IDT) electrodes via UV lithog- raphy. When an alternating electric field is applied onto lithium niobate substrate through the IDT, a SAW, propagating across substrate surface with ten nanometer order amplitudes, is gen- erated. When the SAW meets the liquid which is placed upon substrate, the acoustic energy carried by the wave induces at- omization of the working fluid, which contains salbutamol as a model drug. In order to measure the size distribution of the at- omized droplets, two methods are used. One is the laser diffrac- tion based Spraytec technique and the other is an in-vitro lung modelthe one stage glass twin impinger. The former revealed that the mean diameter of the aerosol atomized was around 3 um which were confirmed by the lung model that demonstrated that nearly 80% of atomized drug aerosol was deposited in the simulated lung area. Moreover, the SAW atomizer only requires 1–3 W driving power, suggesting that it can be miniaturized for portable consumer use. INTRODUCTION Asthma is a chronic inflammatory disorder that is associated with an excessive number of lymphocytes and eosinophil cells in the airway walls [1, 2]. This airway inflammation narrows the respiratory tract and causes airflow blockage or obstruction dur- ing the human respiration process. Pulmonary drug delivery is believed to be an efficient way to treat local lung/chest abnor- malities, such as asthma. Because of the direct target treatment, the inhaled drugs are able to react rapidly at the infected local area with reduced doses and also cause less systemic side ef- fects, comparing to other drug delivery techniques, such as oral and parenteral. [3]. For inhalation therapy to be most effec- tive, the drug-laden aerosols must be deposited predominantly at the inflammation sites of the lung. The inflammation related cells, for example, eosinophil cells, were found in every part of the lung area, from the bronchi to the alveoli, when asthma oc- 1 Copyright c  2009 by ASME Proceedings of the ASME 2009 2nd Micro/Nanoscale Heat & Mass Transfer International Conference MNHMT2009 December 18-21, 2009, Shanghai, China MNHMT2009-18516