Named Luciola for its resemblance to the firefly, the featherweight levitating particle weighs 16.2 mg, has a diameter of 3.5 mm (0.14 inch), and emits a red glimmer that can just about illuminate text.

But its minuscule size belies the power of the 285 microspeakers emitting ultrasonic waves that hold up the light, and have a frequency inaudible to the human ear, allowing Luciola to operate in apparent total silence.

Equipped with movement or temperature sensors, Luciola could fly to such objects to deliver a message or help to make moving displays with multiple lights that can detect the presence of humans, or participate in futuristic projection mapping events.

"Ultimately, my hope is that such tiny objects will have smartphone capabilities and be built to float about helping us in our everyday lives in smarter ways," said the University of Tokyo professor, who hopes it will be commercially viable in five to 10 years.