There is only so much heat or cold that the human body can tolerate. It can be a problem in extreme environments, from sub-freezing arctic temperatures to brutal desert heat, and it doesn’t stop on the ground. Maintaining temperature is also a problem for astronauts. The vacuum of space is a giant freezer, and direct sunlight can be just as brutal as the cold.
Clothing technology that regulates body temperature usually only works in one direction: heating or cooling. They tend to be heavy and require a lot of power, which eventually drains the battery. What if there is a system that heats and cools while running on a constant source of renewable energy?
A team of researchers led by Xiaoyuan Wang of Nankai University in Tianjin, China has developed a flexible, solar-powered device that can be attached to clothing and control the body by effectively heating or cooling the skin. Also, it works continuously for 24 hours and only needs sunlight to charge.
“To achieve the required durability, flexibility and low weight, the body’s thermal management unit must be highly efficient in energy transfer and consume less energy,” the team said in a press release. stadium Recently published in Science.
Battery not included
Wang’s new system combines the power of a solar cell with the power of a photoelectric device. solar cellAlso called photovoltaic cells, are made of semiconductor materials that absorb energy from sunlight and convert it into electricity. In this case, the photovoltaic material used is a flexible polymer.
The other component is a thermoelectric device that changes temperature when placed in an electric field. This field heats up the applied material and cools it down when it is removed.
The system Wang and his colleagues developed is made of a type of polyvinyl. This flexible material acts as an insulator, integrating a solar cell outside the polyvinyl with an electrical device underneath. When exposed to sunlight, the solar cell does exactly what is expected, converting sunlight into electrical energy. This electricity is then transferred to the electrolysis device, where (assuming the device is in cooling mode) the appearance of an electric field heats the device. The solar cells produce enough energy to power the entire system and any excess energy is stored in a separate energy storage unit.
Increase or decrease it
Energy stored during the day becomes especially useful after sunset. In darkness, the system automatically draws power from the storage accessory to continue working throughout the night. Heating and cooling modes can be easily changed when it gets hot or cold And if the system runs out of power, you don’t need to plug anything in – 12 hours of direct sunlight will recharge it.
In the same context, the researchers said: “With these two working modes, bidirectional thermoregulation can be realized, which can be controlled for cooling and heating as needed.” stadium.
So how can an explorer, astronaut or someone living in a harsh environment wear this device? Wang suggests a suit with cooling and heating panels attached to the front and back of the chest, arms and legs. Because the panels are so flexible and lightweight, such garments will not stress anyone exposed to extreme heat.
While this thermoregulation technology may not be available yet, Wang hopes it will represent a major breakthrough for those who must work in harsh environments, even astronauts who must brave the freezing darkness to perform spacewalks.
Science, 2023. DOI: 10.1126/science.adj3654
