Improving and Predicting Fluid Atomization via Hysteresis‐Free Thickness Vibration of Lithium Niobate. (7th December 2017)

• Record Type: Journal Article
• Authors: Collignon, Sean; Manor, Ofer; Friend, James
• Is Part Of: Advanced functional materials. Volume 28:Number 8(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-12-07
• Subjects: actuators -- atomizers -- material optimization -- microfluidics -- nebulizers -- piezoelectric resonators; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201704359
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Acoustically driven atomization from the broad perspective of materials choice, vibration mode, and fluid characteristics is considered to identify a simple method for improving both the understanding of the atomization phenomena and the overall efficiency of atomization. Whether by the definition of a "figure of merit" (a function of the transducer quality factor and electromechanical coupling coefficient), its output vibration displacement at a given input power, or the fluid flow rate during atomization, it is found that the combination of single‐crystal 127.86° Y‐rotated lithium niobate and thickness‐mode vibration produces an order of magnitude greater atomization flow rate and efficiency in comparison to all known atomizers, including classic lead zirconate‐based devices and newer, Rayleigh wave or Rayleigh/Lamb spurious‐mode‐based devices alike. By using this improved approach, for the first time, fluids with viscosities up to 48 cP are reported to be atomized, and an atomization Reynolds number ReA is defined which can be used to both predict the atomization flow rate for ReA ≳ 40 and the inability to atomize a given fluid at a particular vibration amplitude when ReA ≲ 40. Abstract : Through careful consideration of the materials and vibration in piezoelectric media, a counterintuitively superior method is discovered for efficiently and quickly atomizing even viscous fluids from a handheld nebulizer. Using a "figure of merit" defined in terms of the piezoelectric materials and vibration mode, the thickness mode in lithium niobate is found to offer superior atomizer capabilities.