Northeastern University:Squid-​​inspired electronic screens: How one professor builds tech solutions that replicate nature

Assistant professor Leila Deravi takes an interdisciplinary approach to investigating the proteins that drive complex biological systems and building materials in the lab that replicate those systems. Among her research projects are optical displays inspired by squids and a face cream that strengthens skin proteins to reduce wrinkles. Photo by Matthew Modoono/Northeastern University

Elec­tronic screens whose color-​​changing tech­nology is inspired by squids. Skin con­structed in the lab from pro­tein fibers to mimic the aging process and test prod­ucts that may slow it down.

Those are just two of the research projects underway in the lab of Leila Deravi, who joined the North­eastern fac­ulty this fall as assis­tant pro­fessor in the Depart­ment of Chem­istry and Chem­ical Biology.

In Deravi’s inter­dis­ci­pli­nary approach, researchers in chem­istry, mate­rials sci­ence, mechan­ical engi­neering, and physics work together to inves­ti­gate the pro­teins that drive com­plex bio­log­ical sys­tems and then build mate­rials in the lab that repli­cate those sys­tems. Prac­tical appli­ca­tions down the road include tex­tiles and elec­tronic screens that change color by incor­po­rating a squid’s ability to slip from, say, white yellow to brown to merge with the envi­ron­ment. Another is a face cream infused with a chem­ical that Deravi’s team is working on to strengthen skin pro­teins, reducing wrinkles.

“I’ve always been really inter­ested in repli­cating nat­ural sys­tems but using advanced tech­nolo­gies to do so,” says Deravi, who was assis­tant pro­fessor of chem­istry and mate­rials sci­ence at the Uni­ver­sity of New Hamp­shire before coming to North­eastern. Those advanced tech­nolo­gies include for­mu­lating inks con­taining the pro­teins Deravi is studying and using inkjet tech­nology to print out the mate­rials syn­the­sized from them for evaluation.

The university’s con­tin­uing com­mit­ment to expanding inter­dis­ci­pli­nary research makes this a great time for new sci­en­tists like me to be on campus.

— Leila Deravi, assis­tant professor

Deravi praises the Bar­nett Insti­tute of Chem­ical and Bio­log­ical Analysis at North­eastern, where she is a fac­ulty fellow, as a place where her mul­tiple research inter­ests not only come together but also have the oppor­tu­nity to grow. “The insti­tute gives me the ability to tap into fan­tastic resources and exper­tise,” she says.

Inspired by nature

Marine mol­lusks such as the octopus or squid have the uncanny ability to undergo rapid, adap­tive cam­ou­flage, changing the color of their skin within hun­dreds of mil­lisec­onds. Deravi and her col­leagues study organs called chro­matophores that lie just beneath the skin of these ani­mals and con­tain a sac full of pig­ment that may be black, brown, orange, red, or yellow. The ani­mals’ skin color changes as the dis­tri­b­u­tion of the pig­ments shifts to reflect, absorb, or transmit light.

“We have devel­oped a spe­cific extrac­tion pro­tocol that enables us to iso­late these pig­ments,” says Deravi. “Our goal now is to under­stand how they and other protein-​​based struc­tures in the chro­matophore con­tribute to the adap­tive color in cephalopods such as squids.”

Her exper­i­ments address var­ious mind-​​opening ques­tions: What hap­pens to the squid’s pig­ment color when an elec­tric charge is applied to it or light is shone on it? How can her team main­tain con­trol of changes in color that they bring about? When the pig­ments, which Deravi’s team extracts from the ani­mals but also makes in the lab, are inte­grated into nat­ural or syn­thetic fab­rics, will the pro­duc­tion of color-​​changing tex­tiles be possible?

Does this mean that a squid or octopus is essen­tially an under­water elec­tronic dis­play?

— Leila Deravi, assis­tant professor

The researchers have per­formed cal­cu­la­tions showing that the pig­ments also behave like organic semiconductors—they are able to con­duct small amounts of elec­tricity. “Does this mean that a squid or octopus is essen­tially an under­water elec­tronic dis­play?” Deravi asks.

In Sep­tember, she received a grant from the U.S. Army Research Office to answer those and other questions.

The skin research is less far along. “Our first goal is to iden­tify the key pro­teins involved in the aging process,” says Deravi. Col­lagen, elastin, and fibronectin are among them. Next the researchers will con­struct fibers out of the human-​​derived pro­teins they get from a chem­ical com­pany and weave them into a network—in other words, they will con­struct syn­thetic skin. Using custom-​​built machines in the lab, they will then test the mechan­ical prop­er­ties of the fibers over time to explore how aging affects them.

“My appoint­ment is in chem­istry, but I work at the inter­face of chem­istry, biology, engi­neering, and mate­rials sci­ence,” says Deravi. She notes that she finds the recent estab­lish­ment of the Depart­ment of Bio­engi­neering pro­gram at North­eastern par­tic­u­larly exciting. “The university’s con­tin­uing com­mit­ment to expanding inter­dis­ci­pli­nary research makes this a great time for new sci­en­tists like me to be on campus.”