Noncontact Microfluidics of Highly Viscous Liquids for Accurate Self‐Splitting and Pipetting

Abstract

Accurate dosing for various liquids, especially for highly viscous liquids, is fundamental in wide ranging from molecular crosslinking to material processing. Despite droppers or pipettes being widely used as pipetting devices, they are powerless for quantificationally splitting and dosing highly viscous liquids (> 100 mPa⋅s) like polymer liquids due to the intertwined macromolecular chains and strong cohesion energy. Here, we provide a highly transparent photopyroelectric slippery (PS) platform to achieve noncontact self‐splitting for liquids with viscosity as high as 15000 mPa⋅s, just with the assistance of sunlight and a cooling source to provide a local temperature difference (ΔT). Moreover, to guarantee the accuracy for pipetting liquids (> 80%), the ultrathin MXene film (within a thickness of 20 nm) was self‐assembled as the photo‐thermal layers, overcoming the trade‐off between transparency and photothermal property. Compared with traditional pipetting strategies (∼ 1.3% accuracy for pipetting polymer liquids), this accurate microfluidic chip shows a great potential in adhesive system (bonding strength, twice than using the droppers or pipettes).This article is protected by copyright. All rights reserved

Preparation and Wettability Analysis of Metal Biofunctional Surfaces Based on the Microquadrangular Structure

“…In recent years, superhydrophobic surfaces have aroused strong interest from various industries as a result of their potential applications in self-cleaning,, drag reduction,, oil–water separation,, anti-icing, − antifouling and anticorrosion,, biomedical engineering,, and liquid transportation. − To achieve these functions of the material, the key is to adjust the surface adhesion.…”

Portable Triboelectric Electrostatic Tweezer for External Manipulation of Droplets within a Closed Femtosecond Laser-Treated Superhydrophobic System

“…The uneven distribution of charge causes the droplet to be subjected to electrostatic force (Figure d and k). The Coulomb force is the sum of the Maxwell stresses acting on the surface of the droplet: ,− bold-italicF normale = prefix∮ [ ε E false( bold-italicE bold-italicn false) − ε 2 E 2 n ] normald S where ε and E are the permittivity of the liquid and the electric field strength at the droplet surface, respectively, and n and S are the surface unit normal and surface area of the droplet, respectively. This electrostatic force can be quantified in tensor form: ,, bold-italicF normale = prefix∮ T normale , i j · bold-italicn normald S , goodbreak.25em normalw normali normalt normalh .25em T normale , i j = ε 0 ( E i E j − δ i j 2 E 2 ) goodbreak, i , j = x , y badbreak, z where T e , ε 0 , E , and δ ij are the Maxwell stress tensor, the permittivity of air, the magnitude of E , and the Kronecker delta function, respectively.…”

“…The uneven distribution of charge causes the droplet to be subjected to electrostatic force (Figure d and k). The Coulomb force is the sum of the Maxwell stresses acting on the surface of the droplet: ,− where ε and E are the permittivity of the liquid and the electric field strength at the droplet surface, respectively, and n and S are the surface unit normal and surface area of the droplet, respectively. This electrostatic force can be quantified in tensor form: ,, where T e , ε 0 , E , and δ ij are the Maxwell stress tensor, the permittivity of air, the magnitude of E , and the Kronecker delta function, respectively.…”