China develops insect robots that are faster than cockroaches

The BHMbot robot is only 2 cm long and has potential applications in many fields such as search and rescue or checking the structure of mechanical equipment.

Professor Yan Xiaojun and his colleagues at Beijing University of Aeronautics and Astronautics created a 2-centimeter-long insect robot that weighs less than 2 grams, equivalent to two fingernails, China Daily reported on December 2. The new research was published in the journal Science Advances.

The insect robot is 2 centimeters long, weighs less than 2 grams, and has a vertical protrusion the size of two nails. (Photo: Beijing University of Aeronautics and Astronautics).

Miniaturizing robots to insect size is more difficult than building large robots, because bee-sized robots cannot be equipped with traditional motors. Therefore, finding compact power systems has long been a challenge for global researchers.

'Disconnecting from an external power source means integrating batteries and circuit boards into the robot. However, the added weight will make it impossible for the robot to move,' said Liu Zhiwei, associate professor at Beijing University of Aeronautics and Astronautics.

In 2009, Yan discovered an interesting phenomenon: above a certain threshold, DC voltage causes continuous vibrations, a phenomenon usually associated with AC current. This suggested a potential application, such as making wings for small drones.

It wasn't until 2017 that Yan set out to design an insect robot that could move without an external power source. Over the next three years, his team tested dozens of designs and tweaked parameters, but the robot still couldn't move.

To tackle this, Yan studied the movements of beetles, grasshoppers, wild horses, and rabbits. Ultimately, the leopard's jumping and running movements inspired the team to design the biomimetic insect robot BHMbot . The robot runs faster than a cockroach and turns better. It can even walk backwards and perform complex runs under wireless control.

In testing, BHMbot can squeeze through narrow spaces to specific locations to perform tasks. Through a MEMS microphone, it can collect SOS audio signals from Bluetooth speakers buried under bricks and stones, and the audio data is then transmitted to a computer and converted into real sound, Liu said. Equipped with a tiny camera, the robot can also help take pictures inside aircraft engines.

According to Yan, this type of tiny robot has the potential to be applied in many fields such as search and rescue or inspecting the structure of mechanical equipment. They will also be further improved in the future. "Our ultimate goal is to develop a micro drone that flaps its wings and flies like a bee ," Yan added.