Tiny sensors inspired by dandelion (蒲公英) seeds could be spread to the winds to help track of climate change and global warming.
As the climate crisis continues to strengthen, tracking changes in temperature and other environmental signals across a wide area is useful. But doing effectively requires distributing sensors throughout the environment, which can be time-consuming.
"We wondered whether it's possible to build a system that can spread sensors in the wind, rather than having a person go out and place sensors alone, which can be dangerous in hard-to-reach places," says Vikram Iyer at the University of Washington in Seattle.
Iyer and his colleagues used a laser-powered tool to make devices. Each one weighs 30 milligrams with a diameter of 28 millimeters, and has a number of small holes through which air can float in the air like dandelion seeds.
The devices carry tiny sensors, essentially a microcomputer powered by small solar panels that can send back signals to the researchers, who developed different types that can measure temperature, pressure, light and so on. A small capacitor (电容器) can store energy overnight or in cloudy conditions.
In all, the team tested 75 different designs before finding the right mix of variables. The final design can move through the air at 0.87 metres per second, travelling up to 100 metres in a mild wind when released from a drone (无人机). Real-world tests showed that the sensors can transfer data up to 60 metres.
"The production of the ‘seeds' is especially interesting, so is the design of the electronic devices," says Jonathan Aitken at the University of Sheffield, UK. "Both seem to be very strong to the natural environment."
Aitken is also impressed by the range of the sensors' communication abilities. "Plus the cheapness of the device, it means that it can be placed in large numbers, and the communication range makes this an excellent choice, especially within agriculture or disaster area monitoring,'' he says.
