Leila Deravi

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

by Thea Singer

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.

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?

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.”

Originally published in news@Northeastern on November 29, 2016.

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