Researchers at Washington State University have developed a flying robotic bee with potential agricultural applications, such as artificial pollination.

The prototype, called the Bee++, can twist, fly in any direction and achieve the same 6 degrees of free movement that a typical insect can. The tiny robot has four wings made of carbon fiber and mylar and four actuators, devices that control how the individual wings move.

“It’s really exciting,” said the project’s leader, Nestor Perez-Arancibia.

Perez-Arancibia said he can envision robotic insects eventually working “where it’s hard to have live, natural pollinators” — for example, in rain, snow or other conditions that are difficult for honeybees to withstand.

Perez-Arancibia said robots could perhaps also eventually replace honeybees for certain pollination jobs. For example, he suggested California almond growers might use robotic insects rather than bring in live honeybees from other states.

For more than 30 years, researchers have been trying to develop artificial flying insects, said Perez-Arancibia.

Researchers see many possible uses for robotic insects, he said, including for artificial pollination, search and rescue efforts in tight spaces, biological research, environmental monitoring in hostile environments and surgical work.

Perez-Arancibia, now an associate professor in WSU’s School of Mechanical and Materials Engineering, fell into this research around 2010 while working as postdoctoral fellow in a microrobotics lab.

For about 10 years, he and co-researchers have been working to create robotic insects. Early on, he said, they faced many technological challenges. Although much work remains to be done, he said the research has turned a corner.

“The technology is almost there,” he said.

Perez-Arancibia’s team has succeeded in getting the robots to take off and land as insects do.

Earlier iterations had two wings and limited movement. The latest prototype has four wings and more freedom of movement. The front wings can flap in a different pattern than the back wings, allowing the robot to pitch, and the right wings can flap in a different way than the left wings, allowing it to roll.

The researchers also needed the robot to be able to twist in a controlled manner. They took cues from real insects and designed the robot to flap its wings in an angled plane. The tiny robotic bee — weighing 95 milligrams with a 33-millimeter wingspan — can flap its wings about 160 times per second.

The next step, said Perez-Arancibia, is to develop a better power system.

“The main challenge is power,” he said.

The bee can only fly autonomously for about five minutes at a time, so it spends most of its time tethered to a power source with a cable. The researchers are experimenting with different methods of powering the robot, including using fuel, batteries and a laser that recharges batteries while the insect is mid-air.

A person using a so-called “remote control” device can give the Bee++ feedback in real time. Alternatively, the robot can also be pre-programed to follow a trajectory without human supervision.

More work remains to be done, including in artificial intelligence. For the robotic insect to pollinate flowers, for example, Perez-Arancibia said researchers would need to develop an AI system that allows the robot to “see” flowers and trains it to land on them, carrying pollen between blossoms.

“We can design for those things,” he said.

Research article about the project: Published in the journal IEEE Transactions on Robotics

Authors/researchers: Ryan M. Bena, Xiufeng Yang, Ariel A. Calderon, Nestor O. Perez-Arancibia

Funding sources: The National Science Foundation, the Defense Advanced Research Projects Agency, the Washington State University Foundation and the Palouse Club through WSU’s Cougar Cage program