Fabrication and validation of a multi-channel type microfluidic chip for electrokinetic streaming potential devices

Abstract

To elaborate on the applicability of the electrokinetic micro power generation, we designed and fabricated the silicon-glass as well as the PDMS-glass microfluidic chips with the unique features of a multi-channel. Besides miniaturizing the device, the key advantage of our microfluidic chip utilization lies in the reduction in water flow rate. Both a distributor and a collector taking the tapered duct geometry are positioned aiming the uniform distribution of water flow into all individual channels of the chip, in which several hundreds of single microchannels are assembled in parallel. A proper methodology is developed accompanying the deep reactive ion etching as well as the anodic bonding, and optimum process conditions necessary for hard and soft micromachining are presented. It has been shown experimentally and theoretically that the silicon-based microchannel leads to increasing streaming potential and higher external current compared to those of the PDMS-based one. A proper comparison between experimental results and theoretical computations allows justification of the validity of our novel devices. It is useful to recognize that a material inducing a higher magnitude of zeta potential has an advantage for obtaining higher power density under the same external resistance.

Fabrication and electrokinetic motion of electrically anisotropic Janus droplets in microchannels

“…For example, in deionized water, the zeta potential for PDMS microchannel is −60 mV . The zeta potential reduces to −20 mV in 1 mM KCl solution . Therefore, under applied electrical field of 50 V/cm, the electroosmotic flow velocities in a microchannel for deionized water and 1 mM KCl solution can be calculated to be 236.1 and 78.7 μm/s, respectively.…”

Microfabrication of biomedical lab-on-chip devices. A review

“…Their dielectric diversification can be exploited for removing metastatic cancer cells from healthy blood cells. Other electrokinetic means with growing applications in lab-on-chips technology is electroosmotic flow, a coulomb effect that results in transportation of ions of an electric double layer [ 115,116 ], and its reverse effect, streaming potential, that is induced voltage on an electrode due to the flowing motion of counterions of an electric double layer [ 117,118 ].…”

Micro/nanofluidics-enabled energy conversion and its implemented devices

“…The investigation on the device that uses EDL is also underway. The purpose of the study of Chun et al [90] is to investigate the fabrication of a high-density multi-channeltype microfluidic chip for a streaming potential device and to test its potential for applicability in electrokinetic micropower generation. They designed and fabricated silicon-glass and PDMS-glass microfluidic chips with the unique features of a multi-channel [ Fig.…”