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
Carmen Teutsch | Wiley-VCH
Scientist invents way to trigger artificial photosynthesis to clean air
26.04.2017 | University of Central Florida
Researchers invent process to make sustainable rubber, plastics
25.04.2017 | University of Delaware
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Health and Medicine
27.04.2017 | Information Technology
26.04.2017 | Materials Sciences