An adaptive power regulation method of acoustic droplet ejection system for high-throughput liquid transfer.

• When utilizing the acoustic droplet ejection (ADE) system, it is crucial to ensure that droplets fly upward at a specific velocity and efficiently coalesce on the target substrate. This relies on precise adjustment of the acoustic input power. • In this paper, we first utilize the oscillating drop technique to achieve non-contact measurements of surface tension and viscosity. The measurement results of surface tension and viscosity showed a good agreement with that obtained by the standard instruments. • In addition, an adaptive power regulation method was proposed based on real-time detection of the liquid properties. By using the power regulation method, the relative errors between the obtained initial velocity and the given velocity are mostly less than 6.7%. This work not only achieved non-contact and rapid measurement of liquid properties, but also significantly improved the operational efficiency of the ADE system for high-throughput liquid transfer. The constantly evolving pace of life science research has necessitated fundamental changes in liquid handling systems. With its high-throughput liquid handling capability without physical contact, the acoustic droplet ejection (ADE) technology has been proven to be highly beneficial in simplifying experimental operations and enhancing reagent compatibility. And it is becoming one of the important tools in life science research. When utilizing the ADE system, it is crucial to ensure that droplets fly upward at a specific velocity and efficiently coalesce on the target substrate. This relies on precise adjustment of the acoustic input power. However, the existing power regulation methods are either cumbersome to operate or rely on additional devices to measure the liquid properties in advance, making it difficult to meet the demand for rapid and accurate assessment of input power. The determination of viscosity and surface tension is the prerequisite for accurate liquid transfer during the ADE. In this paper, we first utilize the oscillating drop technique to achieve non-contact and synchronous measurements of surface tension and viscosity. The measurement results showed a good agreement with that obtained by the standard instruments. Based on the real-time detection of the liquid properties, an adaptive power regulation method was proposed to precisely control droplet initial velocity. Using the power regulation method, the relative errors between the obtained initial velocity and the given velocity are mostly less than 6.7%. This work not only achieved the measurement of liquid properties, but also significantly improved the operational efficiency of the ADE system for high-throughput liquid transfer. [ABSTRACT FROM AUTHOR]