We often hear that humidity is worse than the heat. Scientists from the National University of Singapore kept this in mind as they recently created a hydrogel that has the ability to absorb moisture from the air. This makes the heat a bit more tolerable. But, this is not all that the material can do.
“Singapore, like many tropical countries, experiences high levels of relative humidity between 70 to 80 per cent,” says Assistant Professor Tan Swee Ching, who led the research. “In a humid environment, the air is saturated with water and as a result, sweat on our body evaporates more slowly. This causes us to feel hotter than the actual ambient temperature, leading to great discomfort. Our novel hydrogel aims to achieve a cooling effect by removing moisture from ambient air very efficiently.”
The hydrogel is primarily made up of zinc oxide. It can absorb over 2.5 times its weight in water vapor and it is not only easy to produce it is inexpensive as well. Furthermore, it performs 8 times better than other drying agents such as silica gel and calcium chloride and does not require any electricity to operate.
“It can be easily coated onto walls, windows and even decorative items (such as a sculpture) to perform the dehumidifying function,” says Tan. The hydrogel will actually be able to bring down the temperature in a room where it is applied to the windows.
This is due to the fact that as it absorbs water, it turns from being transparent to being semi-opaque and effectively blocks 50% of the infrared radiation in the incident sunlight. This makes it capable to decrease the temperature of the room by seven degrees. It can be returned back to the transparent state by applying an electrical current to it.
As the hydrogel is flexible and electrically conductive, it can be used as a conductive ink on circuit boards in electronic devices that are flexible. The gel can easily be removed using a solvent like vinegar when it is time to recycle the boards. You can check out the technology in the video below: