Figure 7.

A metal-SU-8-PDMS hybrid device for multifunctional application. (a) Photo of the device indicated with the fluidic connections; (b) close-up of the device showing five orifices (01–05) and respective electrodes. The fluidic structures, patterned in SU-8, were precisely aligned with Pt electrodes. Blue arrows indicate the flow directions during the microparticle trapping; (c) close-up of a unit for microparticle trapping, nDEP releasing and local impedance measurement. The tip of the tip electrode is right situated under the orifice; (d) micrographs of one trapped microparticle and two vertically stacked microparticles. The diameter of microparticles used in this work is 6 µm; (e–i) identification of single and two vertically stacked microparticle(s) at the orifices 01 to 05 through impedance measurements. $\left|Z\right|$ and $\left|Z_e\right|$ are the impedance magnitudes from measuring the trapped microparticle(s) and the empty orifice, respectively.