If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.



Bioadhesive for sticking sensors on squishy squid

A water-wicking bioadhesive acts like double-sided tape on squid skin

by Fionna Samuels
April 19, 2024

A cartoon drawing of the material matrix that makes up the adhesive designed by Xuanhe Zhao.
Credit: Adapted from Nat. Commun.
The network of polyacrylic acid, polyvinyl alcohol, and esters adheres to marine animals through both covalent amide bonds and physical hydrogen bonds.

The lives of most sea creatures remain largely mysterious. Bound to boats or land, researchers rely on sensors to collect data and piece together how marine animals move through their environments. But attaching portable data collectors to small, squishy beasts like squid is incredibly challenging.

“They needed to suture the sensor to those marine animals,” explains mechanical engineer Xuanhe Zhao of the Massachusetts Institute of Technology. Now Zhao has combined forces with T. Aran Mooney, a marine biologist at Woods Hole Oceanographic Institution, to alter a bioadhesive designed for sealing human wounds. They’ve use it to, instead, stick sensors to delicate marine creatures (Nat. Commun. 2024, DOI: 10.1038/s41467-024-46833-4).

Credit: Courtesy of Xuanhe Zhao/MIT
A researcher uses the newly designed bioadhesive to quickly attach a sensor to a live squid. Once released, the animal swims away normally.

The new adhesive is made from a combination of polyacrylic acid, polyvinyl alcohol, and N-hydroxysuccinimide ester. The network of physically cross-linked polyacrylic acid absorbs water off the surface of a squid’s skin. The covalently cross-linked network of polyvinyl alcohol strengthens the material and acts as a scaffold to which the ester can bind. And the ester forms a covalent amide bond to the squid’s skin.

When dry, the material is stiff enough to be preemptively stuck to the back of a sensor. Then, when the prepped sensor is placed on the wet skin of a captured marine animal, the adhesive’s matrix absorbs water and the adhesive becomes jellylike and sticks to the animal’s flexible skin. “It’s similar to double-sided tape,” Zhao says.

After designing and synthesizing samples, Zhao’s students went out with Mooney to test the material. Not only did it adhere exactly as expected, but it also allowed the scientists to gently tag numerous squid in a short amount of time—no stitches required.



This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.