液柱受到軸向擾動時，擾動會沿著液柱下游成長，最後將液柱分解成一顆顆液滴，此現象稱為毛細不穩定現象，本研究針對此現象，以LTCC為材料，製作出可產生單一粒徑液滴與多種粒徑液滴的微液滴產生器。
LTCC液滴產生器以壓電片帶動LTCC薄板產生振動，產生之振動傳遞給由噴嘴噴出之液柱，最後斷裂形成液滴。液滴產生器的噴嘴以CO2雷射加工製作而成，本研究藉由挑選合適成分的LTCC與調整雷射功率，減少玻璃結晶堆積的狀況，並利用雷射聚焦特性，成功加工出不同尺寸的噴嘴。實驗結果顯示，液滴粒徑與致動器的振動頻率、噴嘴直徑及流體流速有關。在有效的頻率範圍內，液滴粒徑與理論值頗為吻合。

When a liquid jet experiences axisymmetric disturbance, the disturbance grows in space, moves downstream, and eventually breaks up the jet into droplets. The phenomenon is called capillary instability, also known as Rayleigh breakup. Based on this instability, the present study develops droplet generators made of low temperature co-fired ceramics (LTCC). Both the monodisperse and multi-size droplet generators are successfully fabricated.
The LTCC generator is driven by a piezoelectric disc attached directly on a LTCC diaphragm to provide the necessary disturbance. A backpressure is provided to the chamber of the generator such that a liquid jet can be formed steadily through a nozzle. Nozzles with different diameters are manufactured successfully by CO2 laser drilling. It is shown that the proportion of glass in the LTCC green tape and the parameters of laser drilling are key factors in fabricating the nozzle. Results show that the droplet sizes depend on excitation frequency, nozzle diameter and jet velocity. In the range of working frequency, the sizes of the droplets agree well with theoretical predictions.

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