MIT is known for its high-tech innovations. But sometimes, progress comes in very low-tech forms.
In a paper published this week in Nature Energy, MIT researchers lay out a way to create a floating device that turns water into steam using energy from the sun. Also, bubble wrap. The researchers hope that the design could one day be used as a component in small desalination or wastewater treatment plants, and that the low-cost design could last for one to two years.
The device is an improvement over the team’s 2014 version of a solar sponge, which required sunlight to be concentrated to about 10 times the intensity of a sunny day. This new version works outside on a sunny day by taking advantage of the heat-trapping properties of bubble wrap.
The bubble wrap keeps heat from escaping, while a thin layer of copper and a material called a “spectrally-selective absorber” helped turn the sunlight into enough heat to boil the water underneath the floating foam disk..
According to MIT, the inspiration for adding bubble wrap came from the 16-year-old daughter of engineering professor Gang Chen, an author on the paper. Chen’s daughter was using bubble wrap to build a greenhouse for a science project.
“She was able to heat it to 160 degrees Fahrenheit, in winter!” Chen said. “It was very effective.”