Mechanism and stability investigation of a nozzle-free droplet-on-demand acoustic ejector. Issue 18 (11th August 2021)

• Record Type: Journal Article
• Authors: Ning, Yuan; Zhang, Menglun; Zhang, Hongxiang; Duan, Xuexin; Yuan, Yi; Liu, Buohua; Pang, Wei
• Is Part Of: Analyst. Volume 146:Issue 18(2021)
• Page Start: 5650
• Page End: 5657
• Publication Date: 2021-08-11
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/d1an01028j
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : A novel acoustic ejector without a nozzle was proposed for picoliter droplet jetting using a Lamb wave transducer array. Abstract : This paper investigates the mechanism of a new acoustic micro-ejector using a Lamb wave transducer array, which can stably generate picoliter (pL) droplet jetting without nozzles. With eight transducers arranged as an octagon array, droplets are ejected based on the mechanism of combined acoustic pressure waves and acoustic streaming. The acoustic focusing area is designed as a line at the liquid center, which is the key factor for a large working range of liquid height. The experimental results show that the ejector can produce uniform water droplets of 22 μm diameter (5.6 pL in volume) continuously at a rate of 0.33 kHz with high ejection stability, owing to a large liquid height window and high acoustic wave frequency. By delivering precise ∼pL droplets without clogging issues, the acoustic ejector has great potential for demanding biochemical applications.