A company affiliated with the Dutch Frisian Water Campus has devised an innovation that should help against water stress worldwide. “Sponsh” absorbs water at night and releases it during the day. For example, crops can be irrigated in times of drought.
Sponsh is a textile that connects to water molecules in the air via an applied nanocoating – a layer with special properties. The humidity must be sufficiently high for this. The Sponsh cloth then sucks in the water when it is a little colder, usually at night, and releases the water molecules when it gets warmer during the day.
The “piece of fabric”, as co-founder Kurt Hamming calls it, can be hung and absorb up to three times its weight in water. “And at the trigger temperature, he squeezes himself without using energy.”
Forest fires
Hamming joined the founders of Sponsh, Dr. Catarina Esteves, assistant professor at the Dutch Technical University of Eindhoven, and Lourens Boot. ,, Lourens traveled through Portugal with a camper in 2017, when that country had the driest summer ever. Trucks with water were supplied after it had not rained for months. There were violent fires. But he also saw that the clothes that his family had left outside at night were all wet in the morning. That was actually the beginning of Sponsh. ”
Contact with Esteves at TU Eindhoven was established more than a year ago. The Portuguese professor had invented the technology with which Sponsh works. ,, The technique was still very basic. The effect has been proven on a piece of textile measuring one by one centimeters. Subsequently, a scientific publication was published about this, but no one who subsequently took it further in practice. We have now done that. ”
They hope it is a giant step against deforestation and desertification. The temperature-sensitive material is also being worked on in the university’s lab. Startlife from Wageningen University and Climate-Kic from TU Delft, a subsidy for sustainable startups, also helped the project further in the past year. In the city of Leeuwarden, two workplaces have been set up at the Water Campus and the official head office is there. Knowledge has also been exchanged and contacts have been established.
Against water shortage
Sponsh must offer a solution against water shortages. ,, You can use it to irrigate crops in dry coastal areas. I mean dry in terms of rainfall and groundwater level. A humidity of more than 70 percent is needed at night, “explains Hamming. Such circumstances exist in, for example, Romania, Bulgaria, Syria, Lebanon, Dubai, Portugal, South Africa and California.
The founders of Sponsh first focus on the so-called dry farming. Farmers who grow smaller crops, such as fruit and nuts, in areas where you already have to work with little water. “The cloths can then be hung on trees with almonds, or wrapped around it,” says Hamming. ,, Water shortages mean that farmers sometimes suddenly get a water ration. Then you have a big problem with a few hundred hectares of almond trees. Often it is also not possible to hit a well and salinisation makes the situation difficult. There are methods that extract water from the air with electricity, but we are one hundred times as effective. And so you do not need electricity. ”
We are now looking at (technical) textile producers to switch to a production of rolls of fifty to one hundred meters long and one meter wide. Hamming says he prefers to bring production back to the (Eastern) Netherlands after the trial phase. The product will also be affordable for the often poorer areas where it is used. ,, We expect Sponsh to cost between five and ten euros per square meter. A square meter of dust can then produce 1.3 liters of water in a day. ”
Dehumidify greenhouses
If the concept has proven itself, the Sponsh technology could possibly also be used to dehumidify greenhouses. If the windows are now opened for this, a lot of CO2 will evaporate, Hamming knows. An “irrigation box with tap” could also be made for larger agriculture and animal husbandry, and the same applies to a drinking water box, where, ideally, minerals are added to the water.
«Within a few years we want to sell the rolls of cloth on a large scale in several countries. We hope it is a giant step against deforestation and desertification. It must be prevented that farmers have to stop cultivation due to a lack of water. Agricultural land must be maintained with Sponsh. ”