Presentation on theme: "ENERGY HARVESTING THROUGH REVERSE ELECTROWETTING"— Presentation transcript:
1ENERGY HARVESTING THROUGH REVERSE ELECTROWETTING -VINUTHNA C.RDEBOLINA SAHA
2ElectrowettingElectrowetting is a microfluidic phenomenon that changes the surface tension of the liquid on the solid surface on application of voltage.Electrowetting on dielectric(EWOD) –Liquid spreading on the dielectric surface is facilitatedby electrically induced increase in the dielectricsurface wettability.Motion of a conductive liquid on a dielectric-coatedconductive substrate.Wettability change arises from the extra electrostaticenergy that is associated with electrically chargedliquid-solid interface.
3Surface Energy ρ(sl effective)= ρ(sl0) – 1/2CV^2 cosϴ=cosϴ0 + 1/2CV^2 Wiki definition: Surface energy may be defined as the excess energy at the surface of the material compared to the bulk.ρ(sl effective)= ρ(sl0) – 1/2CV^2cosϴ=cosϴ0 + 1/2CV^2
4Contact angleThe contact angle is the angle measured through the liquid, where a liquid/vapour interface meets a solid surface.
5REVERSE ELECTROWETTING Converting mechanical energy of liquid motion into electrical current, thus achieving reverse electrowetting (REWOD).Constant bias voltage between droplet and electrodeExternal mechanical actuation - moves the droplet to force the decrease of its overlap with the di-electric film coated electrodeTom Krupenkin and Ashley TaylorConverts pressure energy into electrical energyLiquid metal alloy- GalinstanInstep Nano power- researchBasic concept - Change in contact angle and surface energy
6How this works ? Capacitance(C) = €0A/d Cmax----->Cmin because of change in effective contact area.
8How to make it efficient? More energy is generated when the conductivity of the fluid is moreElectrode material of low conductivity is preferableUsing more droplets thereby increasing the effective contact areaMaking the channel length moreChallenges….Energy produced is very lessDevice manufacturing for practical purposes
9“Footfalls for phone calls” When we walk our body produces 40 watts of mechanical power as heat when our feet strike the ground.A special electricity-generating cushion placed inside the soles of a regular pair of shoes can transform some of that footfall power into several watts of electricity.Over the course of a single day, the generated energy, which gets stored in a small battery in the sole, provides enough electricity for a pedestrian to extend her smartphone’s battery life