Continuous electrowetting effect

Beni, G.; Hackwood, S.; Jackel, J.

doi:10.1063/1.92952

Cited by 123 publications

(87 citation statements)

References 5 publications

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“…However, unlike (26), in this case, when the motion of the droplet is ceased by the neck of the chamber, the pressure difference across the droplet causes the flow of the surrounding liquid along the channel and thus converts the applied electric potential directly into mechanical movement of the liquid (detailed explanation is given in SI Appendix, section 2). Theoretically, the pressure difference exists continuously along the surface of the Galinstan droplet as long as the electric field is applied, and the principle for the resulting flow motion is called continuous electrowetting, which is an electrical analog to the Marangoni effect (4,26,27). This might also induce eddies within the liquid metal droplet itself.…”

Section: Significancementioning

confidence: 99%

Liquid metal enabled pump

Tang¹,

Khoshmanesh²,

Sivan³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

320

285

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Small-scale pumps will be the heartbeat of many future micro/ nanoscale platforms. However, the integration of small-scale pumps is presently hampered by limited flow rate with respect to the input power, and their rather complicated fabrication processes. These issues arise as many conventional pumping effects require intricate moving elements. Here, we demonstrate a system that we call the liquid metal enabled pump, for driving a range of liquids without mechanical moving parts, upon the application of modest electric field. This pump incorporates a droplet of liquid metal, which induces liquid flow at high flow rates, yet with exceptionally low power consumption by electrowetting/deelectrowetting at the metal surface. We present theory explaining this pumping mechanism and show that the operation is fundamentally different from other existing pumps. The presented liquid metal enabled pump is both efficient and simple, and thus has the potential to fundamentally advance the field of microfluidics.E ngines are systems that convert different kinds of energy into mechanical motion, which are used in various microscale systems, including laboratory-on-a-chip microreactors (1-3), microelectromechanical (MEMS) actuators (4), and microscale heat exchangers (5, 6), to name just a few. Some of the most important members of the engine family are liquid pumps. In the small-scale regime, such pumps can be mainly classified into mechanical and nonmechanical. For mechanical pumps, the driving force is generated by moving parts that are energized using piezoelectric (7), electrostatic (8), thermopneumatic (9), pneumatic (10), electromagnetic (11) effects, or deformation through electrowetting (12). Mechanical pumping systems have several drawbacks, which largely stem from the fact that moving parts cause energy loses due to heat generated by friction and their rather complicated fabrication processes (13,14). In addition, the existence of moving parts increases the potential for failure, which can become acute in complex systems and which could potentially include numerous pumps. Among the varieties of mechanical pumps, only piezoelectric units can produce high flow rates as large as 20,000 μL/min at relatively low input power (>50 mW) (13, 15). However, piezoelectric units generally require operating voltages larger than 100 V (13, 15). Alternatively, nonmechanical pumps with no moving parts generate a driving force using ions energized via electrohydrodynamic (16), electroosmotic (17), or electrochemical (18, 19) effects. However, ion pumps are generally only applicable for low-conductivity liquids, produce relatively low flow rates, and need very high voltages (in the order of kilovolts) to operate (13). Therefore, a pumping system with no moving parts, high flow rate, and low power consumption is ideal for many present-day and emerging applications in microfluidic systems. An ambitious vision is that such pumps can potentially be used for moving small objects on demand, assembling them to create new structures, or could ...

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Section: Significancementioning

confidence: 99%

Liquid metal enabled pump

Tang¹,

Khoshmanesh²,

Sivan³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

320

285

View full text Add to dashboard Cite

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“…The surface tension between the solid-liquid interface is modified by external electric field, which reduces the contact angle. Examples of electrowetting-based microfluidic systems include optical switches [5], digital microfluidic circuits [6], and liquid lenses with variable focal length [7].…”

Section: Introductionmentioning

confidence: 99%

Light actuation of liquid by optoelectrowetting

Chiou

Moon

Toshiyoshi

et al. 2003

Sensors and Actuators A: Physical

215

153

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“…Direct electrical actuation of liquid metal is possible through the manipulation of the liquid metal's surface tension through a phenomenon known as electrocapillarity [60]. Various derivatives of electrocapillarity exist, such as electrowetting (EW) [61], electrowetting on dielectric (EWOD) [62], continuous electrowetting (CEW) [52], electrochemical oxide deposition [50], and electrocapillary actuation (ECA) [3]. Among these liquid-metal actuation techniques, only CEW and ECA fulfill the critera of rapid liquid-metal deformation (∼100 mm/s) with a low-voltage (less than 5V) and low-power electrical signal (µW − mW) [3,52].…”

Section: Future Work: Electrical Actuation Of Liquid Metalmentioning

confidence: 99%

“…The use of electrolytic carrier fluids also allows for surface-tension-based actuation techniques [2,51,52] that are both low voltage and low power. However, aqueous solutions have unacceptably high loss tangents at microwave frequencies [53], and while careful channel design can minimize its impact on device performance [54], some degradation in gain and efficiency is unavoidable.…”

Section: Introductionmentioning

confidence: 99%

Liquid-Metal-Based Reconfigurable Components for RF Front Ends

et al. 2015

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All Rights Reserved AcknowledgmentsI feel that this is a rare opportunity for me to share a bit of candidness and hope to make the most of it. I truly owe the completion of this thesis to many friends and family members and am sorry that I cannot thank you all. hope we can all stay in touch and get a bite and a drink together every once in a while. To leave off I would like to quote Andy Morishita and say "memories are made together" and I will always cherish these past few years we all had. This thesis focuses on the development of liquid-metal-based reconfigurable components for radio-frequency (RF) front ends. Reconfigurable components allow the RF front end to dynamically change key radio parameters such as output power, signal carrier frequency, and bandwidth. These capabilities enable the radio transceiver to adapt to environmental and communication channel changes on the fly, according to programmed protocols and priorities. As a low-loss metallic conductor, the liquid metal Galinstan is well suited for RF applications, and its fluidic nature makes it a natural candidate for reconfigurable architectures. Three liquid-metal based components are described: a frequency-tunable substrate integrated waveguide cavity filter, an electromagnetic bandgap phase shifter, and a frequency-reconfigurable slot antenna. These components are designed, fabricated, and tested and the advantages and disadvantages of using liquid metal are discussed. iv

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Continuous electrowetting effect

Cited by 123 publications

References 5 publications

Liquid metal enabled pump

Liquid metal enabled pump

Light actuation of liquid by optoelectrowetting

Liquid-Metal-Based Reconfigurable Components for RF Front Ends

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