Nature has plenty to teach those in the world of factory automation.

That is the idea behind the Bionic Learning Network (BLN), the brainchild of automation technology supplier Festo. Founded in 2006, the German-based BLN is a research network that looks at how nature handles tasks such as gripping, moving, positioning and control in order to improve the way those functions are performed on the factory floor. The BLN consists of a core team of Festo personnel who work with specialists at the firm, as well as other companies, universities, research institutes and inventors.

“We do not want to copy nature, but learn from nature, to understand the underlying principle and transfer the principle into technology,” says Elias Knubben, Festo’s head of corporate bionic projects and the BLN’s project manager and team leader. Knubben’s BLN teams include professionals from engineering, biology, computer science and other disciplines.

Over the years, the BLN has created a variety of attention-grabbing devices modeled on nature. Examples include a bionic jumping kangaroo, a robot that looks—and flies—like a dragonfly and a penguin-like autonomous underwater vehicle.

Taught by a Tongue

The BLN’s latest trio of creations was unveiled earlier this year. One is a gripper inspired by the chameleon’s tongue. It adapts to the shape and size of the prey enclosed within it.

Modeled on a chameleon’s tongue, the gripper can grab and hold objects with very different shapes. Image credit: Festo Here is how it works. Currently, the grippers used in industrial automation are developed for specific tasks. In facilities that handle multiple products, the gripper must be replaced or modified when the shape of the work piece changes. However, in future plants, something like the BLN’s FlexShapeGripper may be used to handle all kinds of different products, eliminating the need for time-consuming gripper changes.

While a common gripper might be able to pick up either screws or a pencil, , the FlexShapeGripper can pick up screws first and then a pencil without being modified in any way. Moreover, he says the gripper material generates a large amount of static friction that acts as a retentive force.

The FlexShapeGripper is designed to grip a range of objects in a form-fitting manner. The key, is the gripper’s elastic silicone cap, which can adapt to many different product geometries, he says.

Attached to the end of a robotic arm used for positioning, the water-filled cap wraps itself around objects. The force and deformation of the cap can be set with the aid of a proportional valve.

In a single action, the gripper can pick up, hold and set down several objects with different shapes. Both the holding and release mechanisms are pneumatically triggered.

Next on the agenda for the FlexShapeGripper is transformation into an actual product. Festo plans to develop the technology further for “a real customer application,” he says.

Ants as Models

Another BLN project focused on mimicking the anatomy and cooperative behavior of ants. The resulting BionicANTs (ANT stands for Autonomous Networking Technologies) show how individual units can make autonomous decisions and react independently to different situations, while also functioning as part of a single networked system to accomplish a common task. Like a BionicANT colony, future manufacturing systems may feature intelligent components that can adjust themselves to changing conditions.

BionicANTs are designed to look and cooperate like real ants. Image credit: Festo By pushing and pulling together, a small colony of BionicANTs can move loads that a single ant could not budge. In the process, the artificial ants communicate with each other and coordinate their actions just like the real ants. Actions are based on a set of mathematical rules stored in each “ant.”

Using a distributed-intelligence system, all BionicANTs in a colony contribute to the problem-solving process. The ant-to-ant information exchange required for this takes place via radio modules located in their torsos.

Measuring 135 mm long and weighing 105 grams, BionicANTs consist of polyamide components made in an additive manufacturing process called selective laser sintering. Using a 3D MID (Molded Interconnect Device) process, BLN designers integrated visible circuit tracks into the laser-sintered components so the parts can serve as circuit boards while also performing their other functions.

The BionicANT design also features piezo elements, which can be controlled and require little energy and space. For example, the ant jaws’ pincer movement is produced by two built-in piezo-ceramic bending transducers. These deflect when a voltage is applied to them. In addition, the ants can move their legs in different directions thanks to three piezo-ceramic bending transducers located in their thighs.

BionicANT movements are based on information about their surroundings. This data comes from a 3D stereo camera in the head and an opto-electrical sensor in the abdomen. The ants can work for 40 minutes before their batteries need to be recharged. This is done by connecting their feelers to a charging station.

Safe Flying

A third BLN creation unveiled this year is modeled on another common insect—the butterfly. Called eMotionButterflies, the artificial versions feature ultra-light construction and coordinated flying behavior.

Elias Knubben, Festo. When flying in groups, these big blue butterflies avoid collisions thanks to a networked external guidance and monitoring system. The technology, which could be the forerunner of systems that guide and monitor networked factory components, relies on an indoor GPS with 10 infrared (IR) cameras installed where the butterflies take to the air. With two IR markers on its torso, each flying butterfly is tracked. The IR cameras transmit position data to a master computer that coordinates inflight movement.

Each butterfly receives its flight path wirelessly from the master computer, then follows it the best it can. The necessary wing movements are calculated by the butterflies themselves. As the butterflies fly together, the camera system checks their position 160 times per second, and flight-path planning is constantly updated to prevent collisions.

Weighing 32 grams, eMotionButterflies have a wingspan of 50 cm. The wings consists of wafer-thin carbon rods covered with an elastic capacitor film. With a wing-beat frequency of 1-2 Hz, the artificial butterflies can fly at speeds of more than 2 meters per second.

The laser-sintered torsos of eMotionButterflies house a pair of microcontrollers, two servo motors that actuate the wings, an inertial sensor to control flying behavior, a gyroscope/accelerometer/compass unit and two radio modules. Also in the torsos are two battery cells that can power up to four minutes of flight before the butterflies need a recharge.

The capabilities of the latest BLN creations illustrate what can be achieved by a bionics-based design approach.

“Bionics is a source of inspiration, as well as a methodology,” Knubben says. “In the process of developing new technologies, it can stimulate the creativity of engineers, encouraging them to consider solutions that they would never before have contemplated.”

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