Materials scientists at the University of Massachusetts have taken a deep look into the properties of a humble object that might be sticking out of your drink right now: the bendable straw.
The researchers looked at how the straws bend and why they stay bent.
The ability for a bendable straw to remain stable while bent hinges on pent-up tension, or pre-stress, the researchers said in a study published last week in the journal Soft Matter.
“The straw is frustrated, in a sense,” said co-lead author Ryan Hayward, a materials scientist at the university. “There’s no obvious reason why a bendy straw should want to be stable when bent.”
Bendy straws, which can take multiple positions, are “multi-stable,” Hayward said. “The beauty of bistability or multi-stability is that you need to apply force to go in the shape, but then it naturally holds that position.”
The modern bendy straw was invented in the 1930s when Joseph B. Friedman watched his young daughter struggle to drink a milkshake out of a straight paper straw in San Francisco.
Friedman was inspired. He inserted a screw inside the top of a straw and wrapped dental floss around it, outlining the screw’s grooves, according to a 2011 article in The Atlantic.
He removed the screw, “leaving an accordion-like ridge” in the straw, allowing it to bend without blocking the flow of the liquid. He patented it and later created a multimillion-dollar business. Little did he know his work would be studied so closely decades later.
The UMass study paves the way for future research into applications in robotics or devices for minimally invasive surgery, Hayward said.
“It will be helpful for us to understand this fundamental principle, which is key when designing new applications,” Hayward said. “If you’re going to build a reconfigurable device, it’s important to know why it works, and when it might fail.”
The study comes as plastic straws, which gained popularity in the 1950s, have faced scrutiny over the harm they cause to the environment. Plastics can remain in landfills for hundreds of years, and plastic in the ocean floats around as small pieces that can poison animals.
As a result, paper straws are popping up in restaurants and bars.
Material from the Washington Post was included in this report. Katie Camero can be reached at katie.camero@globe.com. Follow her on Twitter @camerokt_