Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists develop new materials that move in response to light

24.07.2018

Elastomeric composites can flex, grip, release, or rotate when exposed to lasers, diffuse light or sunlight

Researchers at Tufts University School of Engineering have developed magnetic elastomeric composites that move in different ways when exposed to light, raising the possibility that these materials could enable a wide range of products that perform simple to complex movements, from tiny engines and valves to solar arrays that bend toward the sunlight. The research is described in an article published today in the Proceedings of the National Academy of Sciences.


A film deflects from a magnetic field when exposed to light.

Credit: SilkLab, Tufts University

In biology, there are many examples where light induces movement or change - think of flowers and leaves turning toward sunlight. The light actuated materials created in this study are based on the principle of the Curie temperature - the temperature above which certain materials will change their magnetic properties.

By heating and cooling a magnetic material, one can turn its magnetism off and on. Biopolymers and elastomers doped with ferromagnetic CrO2 will heat up when exposed to laser or sunlight, temporarily losing their magnetic properties until they cool down again. The basic movements of the material, shaped into films, sponges, and hydrogels, are induced by nearby permanent or electromagnets and can exhibit as bending, twisting, and expansion.

"We could combine these simple movements into more complex motion, like crawling, walking, or swimming," said Fiorenzo Omenetto, Ph.D., corresponding author of the study and the Frank C. Doble Professor of Engineering in the School of Engineering at Tufts. "And these movements can be triggered and controlled wirelessly, using light."

Omenetto's team demonstrated some of these complex movements by constructing soft grippers that capture and release objects in response to light illumination. "One of the advantages of these materials is that we can selectively activate portions of a structure and control them using localized or focused light," said Meng Li, the first author of the paper, "And unlike other light actuated materials based on liquid crystals, these materials can be fashioned to move either toward, or away from the direction of the light. All of these features add up to the ability to make objects large and small with complex, coordinated movements."

To demonstrate this versatility, the researchers constructed a simple "Curie engine". A light actuated film was shaped into a ring and mounted on a needle post. Placed near a permanent magnet, when a laser was focused onto a fixed spot on the ring, it locally demagnetizes that portion of the ring, creating an unbalanced net force that causes the ring to turn. As it turns, the demagnetized spot regains its magnetization and a new spot is illuminated and demagnetized, causing the engine to continuously rotate.

Materials used to create the light actuated materials include polydimethylsoloxane (PDMS), which is a widely used transparent elastomer often shaped into flexible films, and silk fibroin, which is a versatile biocompatible material with excellent optical properties that can be shaped into a wide range of forms - from films to gels, threads, blocks and sponges.

"With additional material patterning, light patterning and magnetic field control, we could theoretically achieve even more complicated and fine-tuned movements, such as folding and unfolding, microfluidic valve switching, micro and nano-sized engines and more," said Omenetto.

###

Other authors on the paper were: Graduate students Meng Li, Yu Wang, Arin Naidu, Carlos Lopez Rodrigues, Bradley Napier and Wenyi Li of the Tufts University SilkLab and the Department of Biomedical Engineering. Aiping Chen and Scott Crooker, Ph.D. of the National High Magnetic Field Laboratory in Los Alamos, NM, helped with measuring and characterizing the magnetic properties of the materials.

This work was supported by the National Science Foundation (#1541959).

Li M, Wang Y, Chen A, Naidu A, Napier BS, Li W, Lopez Rodriguez C, Crooker SA, Omenetto FG. "Flexible magnetic composites for light-controlled actuation and interfaces" PNAS, DOI: 10.1073/pnas.1805832115

About Tufts University/strong>

Tufts University, located on campuses in Boston, Medford/Somerville and Grafton, Massachusetts, and in Talloires, France, is recognized among the premier research universities in the United States. Tufts enjoys a global reputation for academic excellence and for the preparation of students as leaders in a wide range of professions. A growing number of innovative teaching and research initiatives span all Tufts campuses, and collaboration among the faculty and students in the undergraduate, graduate and professional programs across the university's schools is widely encouraged.

Media Contact

Mike Silver
mike.silver@tufts.edu
617-627-0545

 @TuftsUniversity

http://www.tufts.edu 

Mike Silver | EurekAlert!
Further information:
http://dx.doi.org/10.1073/pnas.1805832115

More articles from Materials Sciences:

nachricht First detailed electronic study of new nickelate superconductor finds 3D metallic state
22.01.2020 | DOE/SLAC National Accelerator Laboratory

nachricht A new look at 'strange metals'
21.01.2020 | Vienna University of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Integrate Micro Chips for electronic Skin

Researchers from Dresden and Osaka present the first fully integrated flexible electronics made of magnetic sensors and organic circuits which opens the path towards the development of electronic skin.

Human skin is a fascinating and multifunctional organ with unique properties originating from its flexible and compliant nature. It allows for interfacing with...

Im Focus: Dresden researchers discover resistance mechanism in aggressive cancer

Protease blocks guardian function against uncontrolled cell division

Researchers of the Carl Gustav Carus University Hospital Dresden at the National Center for Tumor Diseases Dresden (NCT/UCC), together with an international...

Im Focus: New roles found for Huntington's disease protein

Crucial role in synapse formation could be new avenue toward treatment

A Duke University research team has identified a new function of a gene called huntingtin, a mutation of which underlies the progressive neurodegenerative...

Im Focus: A new look at 'strange metals'

For years, a new synthesis method has been developed at TU Wien (Vienna) to unlock the secrets of "strange metals". Now a breakthrough has been achieved. The results have been published in "Science".

Superconductors allow electrical current to flow without any resistance - but only below a certain critical temperature. Many materials have to be cooled down...

Im Focus: Programmable nests for cells

KIT researchers develop novel composites of DNA, silica particles, and carbon nanotubes -- Properties can be tailored to various applications

Using DNA, smallest silica particles, and carbon nanotubes, researchers of Karlsruhe Institute of Technology (KIT) developed novel programmable materials....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

The synthesis of bio-based high-performance polyamide from biogenic residues: A real alternative to crude oil

27.01.2020 | Life Sciences

Superfast insights into cellular events

27.01.2020 | Life Sciences

The 'place' of emotions

27.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>