Swiss researchers are developing a tiny, lab-grown diamond that they say could one day enable civilian drones to be recharged mid-flight through a laser.
LakeDiamond, a spin-off of the École polytechnique fédérale de Lausanne (EPFL) in Lausanne, Switzerland, is creating a power beaming system: an energy-rich laser beam that is guided by a tracking system and shines directly on photovoltaic cells on a drone’s exterior.
EPFL notes that the system poses no threat to human health – e.g., to skin or eyes. The development is one of 10 projects supported for two years by the Swiss Space Office. LakeDiamond’s technology is built around diamonds that are grown in the company’s lab and subsequently etched at the atomic level.
The system produces a laser beam with a wavelength of 1.5 µm that, in addition to being safe, can travel much farther without losing strength, explains EPFL.
“Systems developed by other companies and labs, often for military applications, employ lasers that are more powerful and thus more dangerous for humans,” says Pascal Gallo, CEO of LakeDiamond.
On the other hand, this beam has a larger diameter, and its rays remain parallel over a longer distance – in this case, up to several hundred meters.
In LakeDiamond’s laser, the light produced by a diode is directed at a booster composed of reflective material, an optical component and a small metal plate to absorb the heat. The breakthrough lies not with this setup, which already exists, but with the fact that the emitted beam is only a few dozen watts strong, according to EPFL. The secret is using a small, square, lab-grown diamond as the optical component.
The lab-grown diamonds’ key properties include high transparency and thermal conductivity, which took the researchers more than 10 years to develop, says EPFL. LakeDiamond grows its diamonds through a process of chemical vapor deposition, an approach that ensures their purity and reproducibility. The surfaces of the resulting diamonds are then sculpted at the nano level using expertise developed in Niels Quack’s lab at EPFL.
“To achieve greater power – say, to recharge a larger drone – these lasers could easily be operated in series,” says Nicolas Malpiece, who is in charge of power beaming at LakeDiamond.
The company’s remote recharging system works in the lab but will require further development and refinement before it’s ready for field use, notes EPFL.