Qihan Liu's blog

The Labortory of Soft Materials Mechanics and Manufacturing (https://www.engineering.pitt.edu/LASM3/) is recruiting PhD candidates starting either on Spring or Fall 2021. Students with expertise in the following areas are especially valued:

1. Thermodynamics of solids

2. Polymer synthesis

3. Developing customer experimental setups

Please find our new publication in Physical Review Letters on Elastocapillar Crease. This paper has been highlighted by Editors Suggestion.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.098003

ABSTRACT

Bonding hydrophilic and hydrophobic soft materials for functional soft devices

Qihan Liu, Postdoctoral Fellow, Harvard John A Paulson School of Engineering and Applied Science 

Introduction

Please see our recent publication in Extreme Mechanics Letters:

Dear Friends,

Please find our paper on Nature Communications about a novel method to bond hydrogel and elastomers. Comparing to existing methods, our method features the applicability to various manufacturing processes, including dip-coating and 3D printing.

Link to the paper

https://www.nature.com/articles/s41467-018-03269-x

Abstract

A covalent network of polymer can imbibe a solvent to form a gel. In a cavity on the surface of the gel, capillary force may suck the solvent out of the gel to form a pure liquid phase. We show that such osmocapillary phase separation occurs when capillarity balances osmosis, and when the diffusion of solvent in the gel prevails over the condensation of solvent from the vapor. Osmocapillary phase separation can occur even when the gel is isolated from the vapor, or when the solvent is nonvolatile.

Qihan Liu, Shicheng Huang, Zhigang Suo.

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.224301

Our paper in the new journal Extreme Mechanics Letter has come online:  An elastomeric seal may leak by elastic deformation without any material damage. We describe elastic leak using a theoretical model, and watch a seal deform and leak using a transparent experimental setup. The elastomer seals the fluid by forming contact with surrounding hard materials. As the fluid pressure increases, the contact stress also increases but not as much.