New Paper – Soft Slippery Surface Layers!

Some of the most exciting work to come from Chris Johnson’s thesis was the ability to control the dimensions and contact mechanics of polyacrylamide hydrogels by simply starting with different recipes for the hydrogel in the first place. We already knew that the composition controlled the bulk structure, but now we know it controls the […]

Welcome our 2 new lab members Nusrat and Habib

The Spring 2022 semester was a whirlwind of activity, and 2 new group members have joined! Nusrat is joining after finishing her undergraduate degree at Bangladesh University of Engineering & Technology (BUET) in Mechanical Engineering. She is focusing her research on the area of permeability of hydrogels and mentors undergraduates. Habib is joining after earning […]

Congratulations to Chris on his successful PhD defense “Tribological properties of gradient-density hydrogel surfaces”

Hydrated gels are very slippery, and we now know it’s partly due to their surfaces! Chris made composite hydrogels with a soft surface skin, then fully characterized the effective stiffness of that layer, contact mechanics, and how it contributes to good lubrication (or not!) He did an impressively-large number of experiments involving materials synthesis, careful […]

Transition to Fall 2021

So many things are changing around here! I’m excited to jump into this new semester with new teaching spaces, new students, and renewed perspective. Look for some announcements in the coming weeks, but generally, things are looking up. Here are a few reasons why: Everyone in the group is fully vaccinated! We can work in […]

New paper out: Hydrogel surfaces are softer than you think! Published in Experimental Mechanics

Hydrogels are inherently slippery — we know this from touching jello and sliding on banana peels. It’s been shown in many of our prior publications, as well as publications from the Sawyer group (University of Florida), the Spencer group (ETH), the tribology group at Imperial College, and many others. However, making polyacrylamide hydrogels in the […]

New paper out: “Cartilage-like tribological performance of charged double network hydrogels”

While we normally work with single-polymer hydrogels, we had the opportunity to work with the Grunlan group at Texas A&M to study their charged double-network hydrogels. These hydrogels are tough! Looking more like cartilage all the time. In this paper we present evidence that their lubrication behavior matches or exceeds that of native cartilage. Higher […]