micro pump

1. Piezoelectric peristaltic
micropump integrated on a
microfluidic chip
Presented by,
MITHUN T
ROLL NO. 7
S2 THERMAL SCIENCE
CET

2. Introduction
• Micropump is extremely useful in miniature biochemical analysis systems for its
abilities of manipulating and transporting minute liquid.
• The fluid in the microchannel is transported owning to a series of impacting
actions on the microchannel by the piezoelectric actuators.
• Mechanical micropump, a kind of integrated peristaltic micropumps, which
integrates the flexible microchannel in the microfluidic chip
• In the application of “lab on a chip”, miniaturization and large-scale integration,
as well as the cost, power consumption and fabricating complexity reduction, are
becoming the critical elements of micropump
• Various micropumps have been widely used in the applications such as point-of-
care (POC) testing ,drug delivery and microfluidic analysis.

4. Literature review
• Quake’s group designed a pneumatic peristaltic micropump which contained
pneumatic actuators and pumps entirely out of elastomer, to form a microfluidic
large-scale integration
• Albert Folch and others designed a new pneumatic peristaltic micropump by using
3D printing technology
• Huang’s group demonstrated a valve-less microfluidic peristaltic pumping method.
Liquid was pumped by squeezing the microchannels embedded in a poly device with
rolling cams or bearing.
• Xiang’s group designed a linear peristaltic micropump which synchronously
compressed the microfluidic channel with a miniature cam-follower system
• Leow’s group reported a bidirectional micropump using electromagnetic actuator
and separated microchannel.

5. Methods and materials
• Consists of a microchannel and three piezoelectric actuators, the microchannel has
a flexible PDMS (polydimethylsiloxane) membrane as the top layer.
• The impacting actions that compress the chambers, and then squeeze the liquid
out of the chamber into microchannel in two directions
• “1” stands for a pin impacting on the chamber, and “0” for non-impacting on the
chamber, thus a peristaltic period can be expressed as 111-011-001-101-100-110
• Actuators driven by high-speed electric motor each piezoelectric actuator can be
programmable controlled by microcontroller, providing real-time adjustable
travelling wave applied to the peristaltic pump.

7. Micropump system
• To squeeze the liquid in the microchannel, three piezoelectric cantilevers
(QDTE52, PANT Corp,China) were adopted with three micro pins (1356-1 &
1356-3, Keystone Electronics Corp, USA) adhered at the ends of cantilevers
by epoxy adhesive
• Microfluidic chip was fabricated using the standard soft lithography process
• The width w, the height h of the channel and the total thickness of the
PDMS layer were 355.7 μm, 54 μm and 355 μm, respectively.
• The piezoelectric cantilevers were driven by programmable pulse-width-
modulation (PWM) square waveforms (range: DC 60 V–180 V), which were
generated by an FPGA controller circuitry.

8. Mixing on a chip
• Two colored liquids were efficiently mixed at both low and high flow
rates.
• The mixing of biological or chemical species can be applied to digital
polymer chain reaction biochemical analyses nanomaterial synthesis
or emulsification
• The width of inlet of “Y” junction width is 200 μm, and its width of
outlet width is 500 μm, the height of micro channel is 54 μm.
• The work sequences of the two pumps weren’t completely
synchronous, the liquid in the Y junction moved back and forth into
the two pump channels alternately, generating a turbulent flow

10. Results and discussion
• The transported volume has positive correlation with the
displacement of the actuator, which is proportional to the driving
voltage. When the voltage is 90 V and the working frequency is
25 Hz, the flow rate is 8.4 nL/s.
• By adjusting the impacting sequence in controlling program, our
integrated micropump can precisely change flow direction at any
working step
• The flow rate change at the different back pressures. The maximum
back pressure can reach 2.0 K Pa

11. •

12. • The relative mixing index (RMI) was calculated to describe the mixing
effect
Ii shows a local pixel intensity,
I0i represents the local pixel intensity in the unmixed state,
Im shows the average of the pixel intensities in the cross section,
N represents the total number of pixels
where RMI = 1 and RMI = 0 indicate complete separation and complete mixing, respectively

13. Conclusion
• Peristaltic micropump that was composed of separated microfluidic
channel and piezoelectric actuators.
• The unique design of integrating the channel with other functional
microfluidic modules makes it suitable for building a plug-and-play,
conceptual pump-on-a-chip.
• The peristaltic micropump has been successfully designed, fabricated, and
calibrated, showing a high resolution of 8.4 nL/s, and dead volume less
than of 300 nL
• The results of mixing have demonstrated the excellent performances and
high reliability of the micropump, showing great potential for applications
such as point-of-care (POC) testing, drug delivery, and chemical analysis.
• The pulsation of the peristaltic pump is disadvantageous in the application
where a stable flow is required.

14. References
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Khademhosseini, Y.S. Zhang, Fabrication of whole-thermoplastic normally
closed microvalve, micro check valve, and micropump, Sens. Actuators B
Chem. 262 (2018)
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