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Bubbler: A Novel Ultra-High Power Density Energy Harvesting Method Based on Reverse Electrowetting.

Hsu TH, Manakasettharn S, Taylor JA, Krupenkin T - Sci Rep (2015)

Bottom Line: We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics.Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone.This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 UniversityAvenue, Mechanical Engineering Building Room 2238, Madison, WI, 53706, USA.

ABSTRACT
We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse. Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone. This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion. The method can be scaled from a single micro cell with 10(-6) W output to power cell arrays with a total power output in excess of 10 W. This makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible.

No MeSH data available.


Related in: MedlinePlus

EWOD and REWOD concepts.(a) Schematics of the EWOD and REWOD process. The energy is generated during the contact area change. (b) Typical results for the energy generated per unit area per one oscillation cycle as a function of the oscillation frequency. Dots represent the actual experimental data; solid lines represent the best fit2.
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f1: EWOD and REWOD concepts.(a) Schematics of the EWOD and REWOD process. The energy is generated during the contact area change. (b) Typical results for the energy generated per unit area per one oscillation cycle as a function of the oscillation frequency. Dots represent the actual experimental data; solid lines represent the best fit2.

Mentions: As shown in Fig. 1(a), the conventional electrowetting on dielectric (EWOD) phenomenon can be viewed as a process of converting electrical energy into mechanical energy. When electrical voltage is applied between the conductive liquid droplet and the dielectric-coated electrode an electrostatic field builds up at the interface between the liquid and the electrode. In response the droplet moves to increase the area of contact between the droplet and the electrode in order to minimize the free energy of the system3. Thus, in the EWOD process electrical energy is partially converted into mechanical energy associated with the motion of a droplet. REWOD is in essence a reverse process to EOWD, as it converts mechanical energy into electrical energy. External mechanical force is used to periodically deform the droplet and thus induce the change in the area of contact between the droplet and the dielectric-coated electrode, which is connected to the bias voltage source, as shown in Fig. 1(a). This periodic change of the contact area induces the change in the electrical capacitance of the interface and forces electrical current to flow back and forth across the load resistor, producing energy.


Bubbler: A Novel Ultra-High Power Density Energy Harvesting Method Based on Reverse Electrowetting.

Hsu TH, Manakasettharn S, Taylor JA, Krupenkin T - Sci Rep (2015)

EWOD and REWOD concepts.(a) Schematics of the EWOD and REWOD process. The energy is generated during the contact area change. (b) Typical results for the energy generated per unit area per one oscillation cycle as a function of the oscillation frequency. Dots represent the actual experimental data; solid lines represent the best fit2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4645099&req=5

f1: EWOD and REWOD concepts.(a) Schematics of the EWOD and REWOD process. The energy is generated during the contact area change. (b) Typical results for the energy generated per unit area per one oscillation cycle as a function of the oscillation frequency. Dots represent the actual experimental data; solid lines represent the best fit2.
Mentions: As shown in Fig. 1(a), the conventional electrowetting on dielectric (EWOD) phenomenon can be viewed as a process of converting electrical energy into mechanical energy. When electrical voltage is applied between the conductive liquid droplet and the dielectric-coated electrode an electrostatic field builds up at the interface between the liquid and the electrode. In response the droplet moves to increase the area of contact between the droplet and the electrode in order to minimize the free energy of the system3. Thus, in the EWOD process electrical energy is partially converted into mechanical energy associated with the motion of a droplet. REWOD is in essence a reverse process to EOWD, as it converts mechanical energy into electrical energy. External mechanical force is used to periodically deform the droplet and thus induce the change in the area of contact between the droplet and the dielectric-coated electrode, which is connected to the bias voltage source, as shown in Fig. 1(a). This periodic change of the contact area induces the change in the electrical capacitance of the interface and forces electrical current to flow back and forth across the load resistor, producing energy.

Bottom Line: We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics.Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone.This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 UniversityAvenue, Mechanical Engineering Building Room 2238, Madison, WI, 53706, USA.

ABSTRACT
We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse. Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone. This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion. The method can be scaled from a single micro cell with 10(-6) W output to power cell arrays with a total power output in excess of 10 W. This makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible.

No MeSH data available.


Related in: MedlinePlus