New photosensitive film converts light into kinetic energy, bends when irradiated

Researchers at RIKEN have successfully developed a revolutionary new polymer film that changes shape upon irradiation with UV and visible light.

Described in Science, the film is the largest-ever example of a material whose molecular elements are ordered in three dimensions on a macroscopic length scale, marking a breakthrough in techniques for molecular design and processing.

Living organisms depend crucially for their growth and development on their ability to assemble molecules into large, ordered three-dimensional structures. The same assembly processes offer an attractive means for designing materials and devices with novel functions, yet scientists have thus far found such processes impossible to reproduce at a macroscopic scale.

To overcome this impasse, the research group used a structure known as a “polymer brush” made up of a polymethacrylate backbone with outstretched side-chains, which together form a cylindrical shape. Azobenzene molecules, known for their propensity to deform when irradiated, were inserted into the side chains, and a free-standing cast film, created from a solution of the polymer brushes, was then tested for photomechanical response.

When no such response was initially detected, the researchers adopted a different approach, sandwiching the polymer brushes between Teflon sheets to first melt them at 130 °C, then “hot-press” them at 115 °C. The hot-pressing process, they discovered, aligned the main chains of the brushes perpendicular to the film plane, while the side chains oriented themselves horizontally along the stretching direction of the Teflon sheets. The resulting 3D molecular ordering enables the film to literally bend and stretch upon alternating irradiation by UV and visible light.

In converting light energy directly into a mechanical force, this remarkable photoresponsive bending motion breaks new ground in the study of functional materials, suggesting applications in the design of muscle-like biomorphic devices. As a technique, the combination of polymer brushes and hot-pressing vastly expands the scale at which such materials can be manufactured, promising to bring advances from the world of molecular processing to the macroscopic level of our daily lives.

For more information, please contact:

Dr. Takuzo Aida
Functional Soft Matter Research Group
RIKEN Advanced Science Institute
Tel: +81-(0)3-5841-7251 / Fax: +81-(0)3-5841-7310
Dr. Takanori Fukushima
Tel: +81-(0)48-462-1111 ext. 6345, 6349, 6338
Ms. Tomoko Ikawa (PI officer)
Global Relations Office
RIKEN
Tel: +81-(0)48-462-1225 / Fax: +81-(0)48-463-3687
Email: koho@riken.jp

Journal information
Nobuhiko Hosono, Takashi Kajitani, Takanori Fukushima, Kazuki Ito, Sono Sasaki, Masaki Takata, Takuzo Aida. Large-Area Three-Dimensional Molecular Ordering of a Polymer Brush by One-Step Processing. Science (2010). DOI: 10.1126/science.1195302

Media Contact

gro-pr Research asia research news

All latest news from the category: Life Sciences and Chemistry

Articles and reports from the Life Sciences and chemistry area deal with applied and basic research into modern biology, chemistry and human medicine.

Valuable information can be found on a range of life sciences fields including bacteriology, biochemistry, bionics, bioinformatics, biophysics, biotechnology, genetics, geobotany, human biology, marine biology, microbiology, molecular biology, cellular biology, zoology, bioinorganic chemistry, microchemistry and environmental chemistry.

Back to home

Comments (0)

Write a comment

Newest articles

The Sound of the Perfect Coating

Fraunhofer IWS Transfers Laser-based Sound Analysis of Surfaces into Industrial Practice with “LAwave”. Sound waves can reveal surface properties. Parameters such as surface or coating quality of components can be…

Customized silicon chips

…from Saxony for material characterization of printed electronics. How efficient are new materials? Does changing the properties lead to better conductivity? The Fraunhofer Institute for Photonic Microsystems IPMS develops and…

Acetylation: a Time-Keeper of glucocorticoid Sensitivity

Understanding the regulatory mechanism paves the way to enhance the effectiveness of anti-inflammatory therapies and to develop strategies to counteract the negative effects of stress- and age-related cortisol excess. The…

Partners & Sponsors