Researchers have successfully tested a new approach to monitoring the Earth’s atmosphere by using lightweight flying structures that harness sunlight for flight. The innovative device, which utilizes photophoresis, can collect crucial data such as wind speed, pressure, and temperature in the mesosphere, a layer of the atmosphere between 50-85km above the surface.
The team achieved this remarkable feat by developing a nanofabrication process to create a structure so lightweight that its own weight is surpassed by the photophoretic force generated by sunlight. The device consists of a chromium layer on the bottom, which absorbs sunlight, creating a temperature difference between the top and bottom surfaces that lifts the object upwards.
The researchers tested their centimetre-tall structures in a low-pressure chamber, successfully levitating a 1cm-wide structure at an air pressure of 26.7 Pascals by exposing it to light at around 55% of the Sun’s intensity. This experiment modelled conditions 60km above the surface in the mesosphere.
The team believes this device will be instrumental in climate science, providing real-time data on atmospheric conditions that can help calibrate blind spots in current climate models and weather forecasting. The potential applications extend beyond climate science, with possibilities for defence and emergency telecommunication.
While the next step is to integrate onboard communications, researchers are already excited about the possibilities of exploring the upper atmosphere using this technology. With potential uses on Mars and other planets also being explored, this breakthrough has opened up an entirely new class of device that harnesses sunlight for flight.
Source: https://cosmosmagazine.com/science/engineering/light-device-earth-atmosphere