Piezoelectric atomization of liquids with dynamic viscosities up to 175 cP at room temperature

Highlights

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  The proposed structure enables atomization of liquids with a dynamic viscosity up to 175 cP at room temperature.

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  Using multi-dimensional vibration coupling to overcome the lack of energy density per unit of traditional ultrasonic atomizers.

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  The coupled vibrations can cause micro-amplitude elliptical motion to push the liquid forward and cause cavitation effects inside the liquid.

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  Using Laser Doppler Vibrometer to demonstrate that coupled vibrations cause micro-amplitude elliptical motion.

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  Spectroscopic experiments demonstrate the cavitation of the liquid during the atomization process and the unchanged chemical properties of the atomized liquid.

Abstract

Piezoelectric atomization has been applied in the field of respiratory medicine delivery and chemistry. However, the wider application of this technique is limited by the viscosity of the liquid. High-viscosity liquid atomization has great potential for applications in aerospace, medicine, solid-state batteries and engines, but the actual development of atomization is behind expectations. In this study, instead of the traditional model of single-dimensional vibration as a power supply, we propose a novel atomization mechanism that uses two coupled vibrations to induce micro-amplitude elliptical motion of the particles on the surface of the liquid carrier, which produces a similar effect as localized traveling waves to push the liquid forward and induce cavitation to achieve atomization. To achieve this, a flow tube internal cavitation atomizer (FTICA) consisting of a vibration source, a connecting block and a liquid carrier is designed. The prototype can atomize liquids with dynamic viscosities up to 175 cP at room temperature with a driving frequency of 507 kHz and a voltage of 85 V. The maximum atomization rate in the experiment is 56.35 mg/min, and the average atomized particle diameter is 10 µm. Vibration models for the three parts of the proposed FTICA are established, and the vibration characteristics and atomization mechanism of the prototype were verified using the vibration displacement measurement experiment and the spectroscopic experiment. This study offers new possibilities for transpulmonary inhalation therapy, engine fuel supply, solid-state battery processing and other areas where high-viscosity microparticle atomization is needed.