Durga PrabhuToday’s infrastructure mostly consists of big buildings. And such big structures, in most cases, are monostable. Monostable structures are in need of constant input of pressure in order to maintain the stable and inflated state. Most of the inflated structures today are monostable, be it a hospital or a sporting complex. Once the pressure is lost, the poise of that structure is gone too.
Video Credits: nature video, YouTube
In order to address these problem researchers at the Harvard Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), drew inspiration from origami and developed a bistable inflatable structure. This research was published in ‘Nature ‘.
By collaborating the practice and principles of both origami and geometry, the research team was able to come up with a library of triangular building blocks. These building blocks are capable of popping up or folding flat and can be combined in different configuration in order to build closed or multi stable shapes.
These origami structure’s building blocks can be used in different patterns developed through the mix and match technique. With the help of this, the user can create a structure of any shape or size. The researchers demonstrated a number of structures built in different shapes such as archway, an extendable boom and even a pagoda style structure. The researchers were also able to develop shapes consisting of more than two stable forms.
Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS and senior author of the paper said that, “This research provides a direct pathway for a new generation of robust, large-scale inflatable systems that lock in place after deployment and don’t require continuous pressure.”
Image Credits: Benjamin Gorissen/David Melancon/Harvard SEAS
In order to test the durability of their design in the real word, the researchers designed and built a structure contained in the area of 8 foot by 4 foot, which is an inflatable shelter. This inflatable shelter is made out thick sheets of plastic.
Benjamin Gorissen, an associate in Materials Science and Mechanical Engineering at SEAS and co-first author of the paper said, “We are relying on the geometry of these building blocks, not the material characteristics, which means we can make these building blocks out of almost any materials, including inexpensive recyclable materials.”
According to David Melancon who is currently studying PhD at SEAS as is also the co first author of the paper, “You can imagine these shelters being deployed as part of the emergency response in disaster zone.”
He further adds, “They can be stacked flat on a truck and you only need one pressure source to inflate them. Once they are inflated, you can remove the pressure source and move onto the next tent.”
This shelter can be easily set up by one or two people. This is considered to be a fairly easy task compared to the amount of time, work and efforts go into the setting up of today’s military field hospitals, which require at least a dozen people, sometimes even more.
According to Chuck Hoberman, the co author of the paper and the Pierce Anderson Lecturer in Design Engineering at the Graduate School of Design, “We’ve unlocked an unprecedented design space of large-scale inflatable structures that can fold flat and maintain their deployed shape without the risk of catastrophic rupture.”