On‐Demand, Contact‐Less and Loss‐Less Droplet Manipulation via Contact Electrification

Abstract While there are many droplet manipulation techniques, all of them suffer from at least one of the following drawbacks – complex fabrication or complex equipment or liquid loss. In this work, a simple and portable technique is demonstrated that enables on‐demand, contact‐less and loss‐less manipulation of liquid droplets through a combination of contact electrification and slipperiness. In conjunction with numerical simulations, a quantitative analysis is presented to explain the onset of droplet motion. Utilizing the contact electrification technique, contact‐less and loss‐less manipulation of polar and non‐polar liquid droplets on different surface chemistries and geometries is demonstrated. It is envisioned that the technique can pave the way to simple, inexpensive, and portable lab on a chip and point of care devices.