Abstract

Abstract A water droplet sensor based on a flow-through front surface electrode is demonstrated. It is shown that a triboelectric nanogenerator based on a metal-dielectric junction can be utilized to construct simple, self-powered water drop counters that require only a minimum of electronical components. Every water drop generates a flash in a light emitting diode, which is detected by a silicon photodetector located some distance away. Different transducer designs are investigated, either in the form of flat tilted surfaces or polymer-covered metal wires, with the former found to provide the largest charge transfer while the latter is less sensitive to positional stability. It is also demonstrated that the sensor could be utilized to monitor the state of the magnetic field-controlled turbidity of a solution without any additional electronics, thus making a minimalistic design feasible.

Highlights

  • It is well-known that water acquires electrical charge when coming in contact with solid surfaces, and that this can be used to generate electrical currents [1]

  • When hydrophobic fluoropolymer surfaces come in contact with water, negative charge may develop

  • While there is evidence suggesting that the negative charge occurs due to preferential adsorption and/or orientation of O–H groups, and there is significant recent progress revealing the influence of contact line movement, ion concentration and polymer side-groups [65,71,72], the basic mechanism causing the charge transfer is still not fully understood

Read more

Summary

Introduction

It is well-known that water acquires electrical charge when coming in contact with solid surfaces, and that this can be used to generate electrical currents [1]. As the understanding of the process has progressed, the recent few years has seen a range of new self-powered sensors and actuators based on contact electrification of water drop­ lets [2,3,4,5,6,7] The integration of such water-droplet triboelectric nano­ generators in solar cells [8,9,10,11,12,13,14] or wearable items [15,16] has become important. In the current work I investigate a new type water drop energy harvesting system based on the idea of a front-electrode coming in contact with water as presented for water waves in Ref.

Background and working mechanism
The energy harvesting system
Electrical characterization of the energy harvesting systems
Water droplet sensor
Turbidity sensor
Conclusion
Declaration of competing interest
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call