Development and performance test of a micromachined unipolar charger for measurements of submicron aerosol particles having a log-normal size distribution

Dongho Park, Yong Ho Kim, Sang Goo Lee, Chul Kim, Jungho Hwang, Yong Jun Kim

Research output: Contribution to journalArticle

15 Citations (Scopus)


We designed and evaluated a chip-type unipolar charger based on a micro-electro-mechanical systems (MEMS) process for a compact, portable, inexpensive, and easy-to-deploy instrument to measure real-time aerosol particle size distribution with reasonable accuracy. The charger was evaluated using two parameters: particle loss and charging characteristics which were the product of penetration (. p) and average number of charges (. np). Particle losses were below 16.6%, and p. np was approximately proportional to dp2. After evaluation, the number concentrations and the geometric mean diameters of NaCl aerosol particles were estimated using a method presented in Park, An, and Hwang (2007a) and were compared to scanning mobility particle sizer (SMPS) data. To simulate the charger, a commercial computational fluid dynamics (CFD) software, FLUENT (6.3 version), with external user defined function (UDF) code, was used to solve the electric field, flow field, average particle charge, and particle trajectories. The measured data of particle loss, average particle charge, number concentration, and geometric mean diameter were in good agreement with the results calculated by FLUENT.

Original languageEnglish
Pages (from-to)490-500
Number of pages11
JournalJournal of Aerosol Science
Issue number5
Publication statusPublished - 2010 May


All Science Journal Classification (ASJC) codes

  • Environmental Engineering
  • Pollution
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes
  • Atmospheric Science

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