FLATcomp technology applications

Systems based on polymer-DMS bending bars

It looks like the trunk of an elephant, moves gracefully like a viper, and gingerly grasps even raw eggs, tomatoes or a glass of water – a high-tech helper for industry and household. Last year the Bionic Handling Assistant was awarded the German Zukunftspreis, an innovation prize worth 250,000 Euros. This innovative handling system was developed in an interdisciplinary project that was supported by the German federal government and managed by Festo AG in Essling and the Fraunhofer Institute for Production Technology and Automation IPA in Stuttgart. Würth Elektronik was involved every step of the way.

Polymer DMS register the smallest changes in force

“Our printed strain gauges (DMS) give the grasper its feel,” says Dr. Markus Sulzberger, director of product development at Würth Elektronik ICS for company division Printed Electronics. The sensitive “bending bar” sensor system works much like a diving board in a swimming pool. Electrical resistors are attached and if the board bends, the upper resistors are stretched and the ones below are compressed. Our measurement strips respond in the handling system to the smallest changes by conspicuously altering the signal. “Strictly speaking, our sensor elements measure the smallest changes when an object is grasped, moved or let go. Our DMS work with a high degree of precision,” explains Dr. Sulzberger.

Gripper fingers adjust to the object’s contours

The bionic handling system is thus amazingly adaptable and can deal very gently with people and animals. Gripper fingers respond to the contours of the object being grasped and thus ensure the hold of objects of similar size. Other industrial grippers, due to their stiff mechanics and hard materials, cannot ensure the proper grasp of dissimilar objects. In contrast to clumsy, insensitive robots, this new handling assistant can provide support to people without the risk of injuring them, and act as a “third hand” to make work processes easier and faster. Examples for areas of application are inspection and quality control, repairs or cleaning jobs in areas that are difficult to access, and preventive maintenance. Non-industrial applications are also possible. The handling assistant can retrieve food, beverages and medicine and give them to ill and frail persons. Or hand tools to auto mechanics who are making repairs.

Model of the elephant trunk

The highly flexible handling kinematics of gripper, regulation, sensors and control is a fine example of how natural processes and biological principles can be transferred to technology. The design of the bionic handling system is based on the way an elephant trunk works. It has a pneumatic, light construction made of plastic that has lightweight but powerful drives and a sensor system with an ultra-sensitive touch, and comes at a price that is significantly less than that of conventional handling systems and robots.

Patent with future potential

Würth Elektronik quickly delivered its components while the system was being developed. “This provided us with important data for our certification,” says Dr. Sulzberger. Meanwhile, the polymer DMS bending bars have been patented. While looking for new fields of application, a large market has opened up: systems for occupancy recognition! “A goods recognition system reports whenever an article needs to be replenished. The signals come from our sensors” – that’s the vision that will soon be going into production.