Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Machines based on paper and driven by air have been created by scientists at Harvard University in the USA

09.02.2012
These inexpensive robots can stretch, bend and twist under control, and lift objects up to 120 times their own weight. Being soft, they can apply gentle and even pressure, and adapt to varied surfaces.

The fact that paper can bend but not stretch is the key to this remarkable invention, published today in the journal Advanced Functional Materials. Led by Prof. George Whitesides, the researchers have encased a paper sheet in an air-tight elastic material derived from silicones, sometimes called silicon rubbers. On one side of the paper, the silicone is laced with tiny air channels.


Flexible Paper Robots

As air is pumped into the channels (termed PneuNets), the rubbery material on that side expands, forcing the paper to bend. Postdoctoral researcher Ramses Martinez likens the structures to balloons, “When the balloon part of the structure expands it doesn’t become round (as does a child’s balloon), but adopts more complex shapes in response to the constraints imposed by the paper sheets.”

Indeed, quite complicated shapes and movements can be created by simply altering the pattern of channels and by folding the paper in a process the researchers liken to origami. “The methods we developed are astonishingly simple for the complex motions that they generate. Once we understood the materials to use, the best procedures for fabrication and the kinds of designs that worked best.”

Actuators are what scientists call devices that move or change shape in response to some input and are the moving parts of robots. In their Adv. Funct. Mater. paper, the researchers given examples of contracting actuators (the video shows a worm-like one, but some resembling paper lanterns are also demonstrated), elongating actuators, and pleated bellows. One bellows only 8.2 grams itself is shown to lift a 1 kilogram weight – as shown in the image (fig 6 in the article). Restricting movement further by gluing folds or fastening them together with paper strips can cause the shapes to turn corners or twist as they expand. The scientists drew inspiration from the motions of starfish, worms and squid, but used pneumatics and compressed air rather than muscles.

The publication discusses the use of polyester/cellulose paper and a tough siloxane elastomer called Ecoflex®, but Prof. Whitesides and his group have also used materials such as cotton cloth, fiber, and nylon or metallic mesh as the non-stretching base. The production is simple: a mold is used to create pneumatic channels in the elastomer, which is then bonded to elastomer-soaked paper. Compressed air is pumped into the channels through a small valve. Alternatively, for bellows-type operation, a pleated cylinder of paper is soaked in elastomer, the cylinder is capped, and air is pumped into the centre of the cylinder. A strip of elastomer linking the caps ensures the paper returns fully to its original shape and size on the removal of air.

The work combines Prof. Whitesides’ previous experience of “squishy” robots using silicon-based materials and pneumatic activation with his development of paper as a support for tiny, low-cost, ‘microfluidic’ analytical devices.

Dr. Martinez is enthusiastic about the future for the paper robots, “We hope these structures can be developed into assistants for humans. Unlike the types of (machines) robots used in assembly lines (which are designed to be very strong and fast, but they are also very dangerous for humans to be around when they are operating), these actuators can be more ‘human-friendly’. They might, thus, provide ‘extra fingers or hands’ for surgeons, or handle easily damaged structures, such as eggs or fruit.” Use in disaster relief, where ability for machines to navigate complex pathways would be advantageous, is also envisaged. By adding such things as light sources, or metal wires to allow electrical conductivity, potential applications are considerably broadened.

The scientists wish to acknowledge support in part by The Defence Advanced Research Projects Agency (DARPA) and the US Department of Energy.

R. V. Martinez, C. R. Fish, X. Chen, and G. M. Whitesides, “Elastomeric Origami: Programmable Paper–Elastomer Composites as Pneumatic Actuators”, Adv. Funct. Mater. 2012, Vol. 13, DOI: adfm.201202978.

Contacts:

Prof. G. M. Whitesides, Dr. R. V. Martinez
Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA 02138, USA
gwhitesides@gmwgroup.harvard.edu; rmartinez@gmwgroup.harvard.edu
http://gmwgroup.harvard.edu/
Peter Reuell, Harvard University Press Officer
peter_reuell@harvard.edu
Eric Mazzacone, DARPA Public Affairs Officer
Eric.Mazzacone@darpa.mil
The article is available at http://doi.wiley.com/10.1002/adma.20120172978

Carmen Teutsch | Wiley-VCH
Further information:
http://www.wiley-vch.de

More articles from Materials Sciences:

nachricht Research finds new molecular structures in boron-based nanoclusters
13.07.2018 | Brown University

nachricht 3D-Printing: Support structures to prevent vibrations in post-processing of thin-walled parts
12.07.2018 | Fraunhofer-Institut für Produktionstechnologie IPT

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>