A new grant supports professor Kate Jensen’s research with students on the physics of soft adhesives.
Emily Kuwaye ’23 has been working in physics professor Kate Jensen’s lab ever since she was a first-year student. The art major, who says she is deeply interested in physics, helped collect and analyze data about how soft gel microspheres—which are sticky particles barely visible to the naked eye—adhere to surfaces.
The findings in part led to a three-year grant from the National Science Foundation (NSF), announced last fall, that furthers the research and connects Jensen’s lab and students to those of Chelsea Davis, a professor at Purdue University’s School of Materials Engineering. Of the $800,000 grant to both institutions, Williams’ share is about $413,000.
Jensen has been studying soft adhesives for about 10 years, for the most part examining them under “fairly static contexts,” she says. The grant allows her to extend her research to “try to tackle some questions that no one’s ever looked at fundamentally, like what happens when you start to change the shape of an adhesive material?”
The answers could eventually lead to practical uses such as making adhesives whose stickiness could be increased or decreased on demand. Think of soft robots that, like Spider-Man, could climb up walls or walk upside down, or a biomedical or industrial process that involves gently picking up, carrying and releasing delicate components.
At Williams since 2017, Jensen teaches Introduction to Materials Science as well as the course Statistical Mechanics and Thermodynamics. As many as nine students work in her lab year-round.
Though she often crafts her own silicones and gels to analyze under high-powered microscopes, Jensen and her students frequently use the adhesive on the backs of sticky notes as test subjects.
“I’m very fond of sticky notes,” Jensen says. “I mean, they’re so cool.”
Examining them under an electron microscope, she says, “You can actually see there are these little bumps of adhesive material that are around 50 micrometers across”—about the length of a human cell. The students use what they learn to make their own sticky notes.
The NSF grant includes funding for two to three undergraduate research assistants in Jensen’s lab during the academic year, stipends for two summer students and a postdoctoral researcher who can serve as a mentor. The collaboration with Davis also establishes an Adhesion Engineering Summer Camp at Purdue, where Williams students can spend a week each of the next three summers conducting research.
The camp, Jensen says, provides an opportunity for students to “see something that looks very different from Williams—a big engineering school with large-scale engineering facilities—and learn what is engineering, what is a Ph.D. program like, what is engineering research?”
“At Williams, undergraduate students like Emily, with diverse backgrounds and academic interests, are engaging in impactful scientific discovery at a level comparable to that of a major research university,” Jensen adds. “It’s a truly unique research and educational environment, and I’m thrilled to be a part of it.”
Kuwaye, too, recognizes the value of this kind of opportunity: “Doing work in the lab teaches you a lot about problem-solving and critical thinking that can be applied to any discipline.”
STICKY SCIENCE @ HOME
As part of physics professor Kate Jensen’s research, she and her students make soft adhesives to create their own sticky notes. You can try it at home with this recipe:
1 tsp. gelatin powder (unflavored)
1 Tbsp. water
1 Tbsp. glycerin (also sold as glycerol, available at most pharmacies)
1 piece of paper (cut up into note-sized pieces)
• Using a fork or small whisk, mix together the gelatin and water in a small, microwave-safe bowl or mug.
• Add the glycerin, and mix thoroughly. The mixture should be very thick and paste-like, with no large lumps.
• Wait at least 5 minutes for the gelatin to fully hydrate, stirring occasionally.
• Next, microwave the mixture on high for 20-30 seconds, watching that it doesn’t boil over.
• Whisk the hot mixture into a thick, frothy foam and continue mixing.
• As the foam starts to cool, the gelatin will begin to set, and the mixture will start to get noticeably thicker and more viscous. As soon as this happens, use a knife to spread a thin, smooth layer of the foam onto the pieces of paper where you want them to be sticky. If it’s gotten too thick to spread smoothly, just reheat for 10-15 seconds in the microwave and remix.
• Lay the pieces of paper out to finish cooling with the sticky side up. Enjoy your sticky notes!
Note: This recipe sticks best to smooth surfaces like wood, glass, plastic and metal. To make even stickier notes, use a bit less gelatin and/or more glycerin.