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 […]
I have started many posts this way, but in fact we keep discovering more reasons. I’m thrilled to share that our recent work shows how hydrogel surfaces have an innate structure that allows them to maintain robust low friction: a gradient layer. When you submerge a hydrogel into a water bath, the polymer chains want […]
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 […]
Please join me in congratulating Jiho on his new position as a full-time faculty of Mechanical and System Design Engineering at Hongik University. I met Jiho the first week after arriving at Illinois, so my work over the past 7 years and success have always included him, and depended upon him! He graduated in 2020 […]
Latch mechanisms are one of the most fun mechanical systems, yet we rarely teach about them, or research them. When the ketchup bottle is open and closed, the problem is solved. But what if that little snap didn’t just hold the lid closed, but was designed to snap open a huge structure? That’s what the […]
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 […]
It was beautiful weather, and Shab outlasted us all in the soccer circle. Congrats again! And thanks to Lalith and Jiho for beautiful photos.
Many researchers are aware that hydrogels, even a single kind of hydrogel (polyacrylamide) can be designed to have properties that range from brittle to viscoelastic. It’s truly a versatile material! As hydrogels are being considered as replacements for cartilage in the body, they need to be able to take a beating: they can’t break under […]
We had the nice chance to collaborate with Kyle Schulze at Auburn University to put together a review. Check it out to get some good resources for your next paper or proposal! https://rdcu.be/b9jwq
Hydrogels are the next “engineering material” that we need new textbooks for, to teach the next generation of engineers to design with them. Shabnam’s work contributes directly to that, and over the past 4 years she has discovered that the material nature of the hydrogel determines how it wears away — sometimes it acts brittle, […]