Dual light-activated microfluidic pumps based on an optopiezoelectric composite

Abstract

In this paper, a new type of microfluidic pump that can be activated and controlled by a masked light source is presented. The actuation of this micropump is based on an optopiezoelectric composite. This composite is constructed by having one of the electrodes of a piezoelectric PVDF (polyvinylidene fluoride) polymer replaced by a layer of TiOPc (titanyl phthalocyanine) photoconductive coating and an ITO (indium-tin-oxide) transparent electrode. This layer of photoconductive electrode provides the capability to activate multiple locations of this optopiezoelectric composite independently using a masked light source and a single voltage source. To verify the feasibility of this concept, dual light-activated microfluidic pumps based on this optopiezoelectric composite are implemented and studied. Experimental results verify that two microfluidic pumps can be created by one optopiezoelectric composite and that each pump can be optically turned on and off independently or be turned on simultaneously. These results suggest that integrating an optopiezoelectric composite into a lab-on-a-chip system can reduce the size and the number of driving units significantly, since every operation can be done optically and only one driving source is needed. The equivalent circuit, design, and implementation of dual light-activated optopiezoelectric micropumps are discussed in this paper.

Light-activated piezoelectric linear motor by using a serial bimorph made of an optopiezoelectric composite

“…The experimental finding showed that the moving velocity started to decrease at higher frequency range but increased a bit at 800 Hz and 1.2 kHz, as shown in figure 9(f). This result matched the experimental findings in our previous work in optopiezoelectic micropumps [9], where an optimal condition could be achieved using identical frequencies for both light source and driving signal. Thus, the light induced electron-hole pairs could be thoroughly used during each cycle, where excess electrons and holes could be depleted during the light-off state.…”

“…In addition, TiOPc photoconductive coating provides excellent flexibility due to its polymer-based resin. Taking these superior characteristics, we previously reported on creating a microfluidic pump based on an optopiezoelectric composite composed of a TiOPc photoconductive layer and a piezoelectric PVDF (polyvinylidene fluoride) polymer [9]. Using a high concentration of TiOPc, two separated micropumps could be activated optically.…”

Fluorinated Polymers as Smart Materials for Advanced Biomedical Applications

“…In both studies referred previously, it was also observed an increase on the temperature of the transducer surface, and therefore inside the microfluidic system, which is advantageous for applications that require specific heating. A microfluidic pump that has the ability of being activated and controlled by a masked light source was also developed and it is based on an optopiezoelectric composite [ 221 ]. This composite is composed by a piezoelectric PVDF transducer with one of the electrodes replaced by a layer of titanyl phthalocyanine (TiOPc) photoconductive coating and an indium-tin-oxide (ITO) transparent electrode.…”

Smart and Multifunctional Materials Based on Electroactive Poly(vinylidene fluoride): Recent Advances and Opportunities in Sensors, Actuators, Energy, Environmental, and Biomedical Applications

“…(f) Photographs of (i) the dual light-activated optopiezoelectric PVDF pumps, (ii) dip-coated TiOPc/PVB photoconductive layer. Reproduced with permission from ref . Copyright 2017 Institute of Physics Publishing.…”

“…High controllability of the fluidic process is obtained with flow rates ranging from 13 to 135 μL·min –1 . Dual light-activated optopiezoelectic microfluidic pumps based on a 9 μm thick commercial piezoelectric PVDF polymer film coated with a layer of titanyl phthalocyanine (TiOPc) photoconductive coating and ITO transparent electrode were fabricated and tested (Figure f). , They feature the advantage of being selectively activated and controlled, both spatially and temporally, by a single masked light source and voltage source, allowing operation of various micropumps independently at the same time. This approach allows to reduce the complexity and size of the driving element of a microfluidic system.…”