When we hunt for new ways to construct buildings, we are often brought full circle to the past. This week we wanted to explore some of the new and more interesting building methods and materials with unique inspiration from past inventions. How do these new materials and methods work? What concepts do they take from chain mail and origami?
Chain Mail and Coffee Bean Inspired Fabric
In a study published in Nature in August 2021, a group of researchers developed a structured fabric with mechanical properties that can be adjusted. Wang et al. gathered inspiration from woven fabrics like chainmail, and coffee beans, to develop their design.
Consisting of three-dimensional particles that are fit together in an interlocking pattern, the fabric can conform to different and complex shapes.
Pressure makes the sheet of particles jam together and makes the material 25 times stiffer. The pressure needed to lock up the fabric is small, around 93 kilopascals.
The researchers put pressure on the fabric by enclosing it in a flexible envelope and pumping the air out. The motivation for this was coffee beans that are vacuum sealed.
By putting pressure at the boundaries of the fabric, the particles lock up. Interlocking particles have high tensile resistance. The exact strength of the material depends on the shape of the particles and how much surface area is touching. The shape of the particles for this fabric were designed to have as much surface area touching, like chain mail.
The authors anticipate that the structure could be scaled up for emergency or temporary bridges or other structures. Since vacuum packing isn’t functional for a large scale application, the next step in the development is to create a new process to jam up the material.
Emergency Structures Using Origami
Quickly deployable structures have many uses, primarily in emergency situation. Currently, there are two main emergency structures used. Interconnected metal bars with fabric over it, like large tents, or inflatable units. The tent structures can be complicated and hard to set up, but the inflatable units aren’t strong.
In the search for quickly erected structures that are also strong, researchers from Harvard University have turned to origami. Origami is able to make a 3D figure from a 2D piece of paper. Origami primarily uses triangles, and the geometry of triangles is what the researchers used to develop their structure.
The Harvard design starts out as a flat folded structure, much like origami when it is flattened. The system uses pneumatic pressure to open the structure. At this point the pressure can be removed and the system stays rigid. One operator with one pneumatic pump could erect many structures in a few hours.
The team at Harvard first created a series of structures – an arch, starbursts, and flowers. While the idea of using origami in this way isn’t new, the researchers at Harvard are the first to scale the idea. They next created a 2 meter tall structure – taking the concept one more step closer to reality.
This concept could move past the emergency structures and into more traditional architecture. The authors think it could be a partner to traditional building materials. It could help to better control heat and natural light by changing the structure of an embedded origami component.