Abstract:Over the last decade electrical batteries have emerged as a critical bottleneck for portable electronics development. High-power mechanical energy harvesting can potentially provide a valuable alternative to the use of batteries, but, until now, a suitable mechanical-to-electrical energy conversion technology did not exist. Here we describe a novel mechanical-to-electrical energy conversion method based on the reverse electrowetting phenomenon. Electrical energy generation is achieved through the interaction o… Show more
“…Over the last decade, power supplies have become a critical bottleneck for the development of wireless sensor networks due to the limited lifetime of batteries and the requirement of regular replacement or recharging [1,2]. Energy harvesting from ambient wasted energy to generate sustainable electricity for low-power electronic devices is becoming increasingly attractive as an alternative to conventional batteries.…”
“…Over the last decade, power supplies have become a critical bottleneck for the development of wireless sensor networks due to the limited lifetime of batteries and the requirement of regular replacement or recharging [1,2]. Energy harvesting from ambient wasted energy to generate sustainable electricity for low-power electronic devices is becoming increasingly attractive as an alternative to conventional batteries.…”
“…Their working principle is invariably based on the transport of a solid or liquid medium with adsorbed charge to a location of higher electrical potential by continuous application of a mechanical force, typically with low efficiency 2 . Microfluidics technology stands out by its versatility and wide applicability, especially when using electrical control methods [3][4][5][6][7][8][9][10] . Micro-and nanofluidic energy conversion systems have recently been studied using the streaming potential phenomenon.…”
The strong demand for renewable energy promotes research on novel methods and technologies for energy conversion. Microfluidic systems for energy conversion by streaming current are less known to the public, and the relatively low efficiencies previously obtained seemed to limit the further applications of such systems. Here we report a microdropletbased electrostatic generator operating by an acceleration-deceleration cycle ('ballistic' conversion), and show that this principle enables both high efficiency and compact simple design. Water is accelerated by pumping it through a micropore to form a microjet breaking up into fast-moving charged droplets. Droplet kinetic energy is converted to electrical energy when the charged droplets decelerate in the electrical field that forms between membrane and target. We demonstrate conversion efficiencies of up to 48%, a power density of 160 kW m À 2 and both high-(20 kV) and low-(500 V) voltage operation. Besides offering striking new insights, the device potentially opens up new perspectives for low-cost and robust renewable energy conversion.
“…[42][43][44][45][46][47][48][49][50][51] For a droplet on a solid or liquid surface, there is no driving force for droplet motion in the equilibrium state. When a wettability gradient is generated on the surface (Figure 2), imbalanced forces can be produced on the two opposite sides of the droplet.…”
Section: External-field-induced Directional Liquid Motion On a Surfacementioning
External‐field‐responsive liquid transport has received extensive research interest owing to its important applications in microfluidic devices, biological medical, liquid printing, separation, and so forth. To realize different levels of liquid transport on surfaces, the balance of the dynamic competing processes of gradient wetting and dewetting should be controlled to achieve good directionality, confined range, and selectivity of liquid wetting. Here, the recent progress in external‐field‐induced gradient wetting is summarized for controllable liquid transport from movement on the surface to penetration into the surface, particularly for liquid motion on, patterned wetting into, and permeation through films on superwetting surfaces with external field cooperation (e.g., light, electric fields, magnetic fields, temperature, pH, gas, solvent, and their combinations). The selected topics of external‐field‐induced liquid transport on the different levels of surfaces include directional liquid motion on the surface based on the wettability gradient under an external field, partial entry of a liquid into the surface to achieve patterned surface wettability for printing, and liquid‐selective permeation of the film for separation. The future prospects of external‐field‐responsive liquid transport are also discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.