This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Ion drag electrohydrodynamic (EHD) micropumps are promising in a number of micro-scale
applications due to its small form factor, low power consumption, ability to work with dielectric heat transfer
fluids, good controllability and absence of any moving parts. Ion drag EHD micro-pumps have been studied
widely and the pressure head has been reported to depend on electrode material (i.e., work function),
geometric configuration, electrode surface topology and applied electric field. One drawback of such pumps
is the relatively low pressure head generation and high threshold voltage required for the onset of charge
injection for practical applications. The presence of micro/nano features with sharp asperities on the emitter
electrodes is likely to enhance the local electric field and charge injection significantly and thus, the pressure
generation. The objective of this work is to investigate the effect of surface topology on the charge injection
and pressure generation in HFE 7100. Experiments were performed using micropumps with smooth and
single wall carbon nanotube (SWCNT) deposited on smooth gold electrodes. A lower threshold voltage,
higher charge injection and pressure head was found for the micropump with SWCNT deposited on smooth
electrodes compared to the no deposition case
