Monitoring sessile droplet evaporation on a micromechanical device

Prasad, A. , Lin, A.T.-H., Rao, V.R. and Seshia, A.A. (2014) Monitoring sessile droplet evaporation on a micromechanical device. Analyst, 139(21), pp. 5538-5546. (doi: 10.1039/C4AN01389A) (PMID:25199661)

Abstract

A bulk acoustic mode micro-electro-mechanical dual resonator platform is utilised to study the evaporation of sub-microliter water droplets from the surface of the resonator. An analytical formulation for the observed frequency shift and the measure dependence of resonant frequency on the modes of evaporation which is consistent with the optically derived data. The resonators access only a thin layer of the liquid through shear contact and, hence, the response is not affected by the bulk mass of the droplet to first order. A relationship between the droplet contact area and the elapsed time was established for the evaporation process and is used to derive a value of the diffusion coefficient of water in air that is found to be in reasonable agreement with literature values. This work introduces a new tool for the electro-mechanical monitoring of droplet evaporation with relevance to applications such as biosensing in liquid samples of sub-microliter volumes.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Prasad, Dr Abhinav
• Authors: Prasad, A., Lin, A.T.-H., Rao, V.R., and Seshia, A.A.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Analyst
• Publisher: Royal Society of Chemistry
• ISSN: 0003-2654
• ISSN (Online): 1364-5528
• Published Online: 18 August 2014
• Copyright Holders: Copyright © 2014 The Royal Society of Chemistry
• First Published: First published in Analyst 139(21): 5538-5546
• Publisher Policy: Reproduced under a Creative Commons License