MIT's redesigned insect-sized robot flaps its wings and flies 100 times longer

Weighing less than a gram, the robots have wings that can flap, not only extending their flight time but also increasing their agility - enough to do somersaults and trace the infinity symbol in the air. Their average speed is 11.8 inches per second (30 centimeters per second), which is faster than fruit flies.

The microrobot is significant because it could provide a precise way to artificially pollinate plants in multi-story warehouses, allowing large-scale growing of fruits and vegetables indoors and reducing the need for vast farmland.

Over the past few years, bees have declined by the millions, if not billions, around the world due to the harsh effects of pesticides and loss of habitat. A recent survey conducted this year found that more than 200 commercial beekeepers in the United States reported an average loss of more than 50% of their bee populations, with an estimated economic impact of more than $139 million.

So, how can you build a better bee robot? The previous design had eight wings arranged in sets of two. It was found that the wings were arranged in such a way that they blew air against each other as they flapped, reducing lift.

The team updated their approach, reducing the number of wings from eight to four. This not only stabilizes the wings and improves their ability to lift the subroutine off the ground, it also frees up space for more electronic components.

The wings are connected to precisely assembled actuators that act like artificial muscles to generate energy, causing the wings to flap.

The soft actuators used in these wings are made from layers of elastomer sandwiched between thin carbon nanotube electrodes rolled into a cylinder - a kind of artificial muscle. When these muscles rapidly compress and lengthen, they create mechanical force that causes the wings to flap.

Each robot fits within a 1.575-inch square area and has only four wings instead of the eight common in previous microrobot designs.

The improved design ensures that these artificial muscles experience less stress during high-frequency movements. In addition, the hinge has been lengthened to better withstand the pressure of flapping wings. Each robot can be placed in a 4cmx4cm (1.575x1.575in) square space.

Redesigned microrobots are already capable of somersaults and precise trajectory tracking, such as the letters M-I-T seen in multiple exposure shots

These changes allow the microrobot to fly for up to 17 minutes at a time while moving faster than any previous design and performing body rolls and double somersaults. This means they can effectively cover intended flight paths and make precise maneuvers.

These robots could one day help with the task traditionally performed by bees of pollinating plants to grow fruits and vegetables

Researchers believe there is room for further improvement of these micro-aircraft: using new designs to extend flight time to 10,000 seconds; installing batteries and sensors in the space freed up by reducing the number of wings; and improving flight accuracy so that they can take off and land from the center of flowers. This enables a range of applications outside the laboratory, including mechanical pollination in vertical farms.