Ancient Japanese paper art kirigami inspires MIT and Harvard scientists to design non-slip shoe sole
Fashion invokes art within its creation and displays beauty, style, and glamour in the form of clothing, shoes, accessories, and more. In a way, it is art depicting the culture and portraying artistic expression. Fashion is heavily influenced by novelty or newness and powered by style or trends. Most of all, it depends on groundbreaking offerings that transform the way we see ourselves or express ourselves. Scientists have developed a new cutting-edge shoe that will not only make a fashion statement but will prove useful when walking on slippery surfaces. And it is all thanks to art!
Researchers at Massachusets Institute of Technology (MIT) have borrowed from the ancient Japanese paper art, kirigami, to develop an innovative shoe with non-slip soles. The intricate art of paper cutting and folding has been adapted into a kirigami-inspired sole, which becomes spiky when flexed and adds a grip to the bottom of the shoe, especially when trudging on a slippery surface. These shoes may essentially prevent fatal falls, with the enhanced grip that the sole provides.
The new kicks developed by researchers at Harvard John A Paulson School of Engineering and Applied Sciences (SEAS) and MIT are detailed in the paper published in the journal Natural Biomedical Engineering. “Falls are the leading cause of the death for older adults and the second leading cause of occupational-related deaths,” said Giovanni Traverso, an assistant professor of Mechanical Engineering at MIT and co-corresponding author of the paper. “If we could control and increase the friction between us and the ground, we could reduce the risk of these types of falls, which not only cost lives but billions of dollars in medical bills every year", he added.
Researchers used the kirigami technique to mimic snake scales, per Harvard. The gripper under the sole is made of thin, malleable steel sheet with dozens of cuts that look like scales. When the material is stretched, the cuts pop out like spikes and dig into the ground causing friction. When the material contracts, the spikes retreats and smoothes into the sole. “As you walk, the curvature of your shoe changes,” said Sahab Babaee, a fellow research scientist at MIT and co-lead author of the paper. “We designed these assistive grippers to pop-out when weight shifts from the heel to the toe and the shoe bends and stretches along the soles.”
The team extensively studied the human gait to derive the exact curvature of the foot, and determine the right angle that will trigger the spikes with ease. They tested the prototype on multiple surfaces, even ice. “Through a combination of simulations and experiments, we carefully choose where to make the cuts so that the spikes are stiff and pop out at the best possible angle of attack to maximize the grip of the kirigami with the contacting surface,” said Ahmad Rafsanjani, a former postdoctoral fellow at SEAS and co-lead author of the paper.
The shoes don't weigh much and are easier to slip on and off in comparison to the commercial kicks that we usually tend to buy. In addition to that, the shoes nailed the initial tests by outperforming a normal pair in creating friction. “These lightweight, kirigami metasurfaces could play an important role in public health to mitigate slipping and falling in a range of different environments,” said Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS and co-corresponding author of the paper. “They could also be used to improve the mobility of all-terrain robots that could one day travel across difficult environments for search and rescue missions.”
What is kirigami?
Derived from the words 'kiru', meaning to cut and 'kami' meaning paper, kirigami is a Japanese form of paper art, similar to the famed traditional origami technique. But while origami is based on paper-folding techniques, kirigami offers the artist a bit more creative freedom through the skillful use of cuts and snips (with a scalpel or scissors) within their creation. It is created from a single sheet of paper and incorporates folds, with occasional cuts to suit the design which culminates in a 3D piece.
How long has it been around?
Origami and kirigami's origins can be traced back to ancient China, where paper was invented around 105 AD. The Chinese began using colored paper to make decorative cutouts called 'Jiǎnzhǐ' in the 6th century. Initially, they were used for religious purposes and the paper creations were meant to honor gods and ancestors. However, it later evolved into a pleasure activity that women and children indulged in.