Gripping Success with Both Hands: With Ashkan Rajenzad and Dr Antonio Forte

From helping care for the elderly, increasing factory production and even exploring space, robotics could deliver meaningful change, with some reports suggesting automation could increase global productivity by up to 1.4% annually by 2030.

Fresh off their latest article on robotic picking with Dr Matthew Howard and Professor Chris Lorenz being chosen for the frontispiece for the journal Advanced Functional Materials, Engineering PhD student Ashkan Rajenzad and Dr Antonio Forte talk about their latest design innovation in The Weird Gripper company, and how it’s changing the automation game.

What is mechanical picking and why is it so important?

Dr Antonio Forte: Robotic picking is when robotic arms or grippers pick, harvest or package produce or herbs, often on a factory line. Without efficient picking and packing, the food in our shops doesn’t get there on time.

Major world events like the COVID-19 pandemic have meant that this very time sensitive practice of handling fresh produce before it goes off has been hit with big labour shortages – with less people picking food, the costs to make up for that shortfall often gets pushed onto consumers.

Ashkan Rajenzad: This is where robotic picking can come in and help offload some of the manual labour from agricultural jobs and plug those shortages. Automation is a major need in the sector, but traditional picking tools have failed to get a grip on the vast range of objects they come across. They rely on suction cups to grab produce like a plunger, and while that works for foods with a smooth, hard surface like a courgette, the catch-all approach can’t pick up soft, tangle-prone food like herbs or mesh bags for fruit.

That’s where the design we patented with our spin-out The Weird Gripper Company helps. Instead of a suction cup, we use tangling to quickly and efficiently pick up produce with a new, completely food-safe synthetic material.

How does your most recent paper compliment the design?

AR: The new paper builds on this idea of entanglement to make it almost entirely programmable, exploiting the geometry of tangling for our own purposes.

We designed several different sizes of magnetic grains and found that when they are dropped on something soft and tangle-prone, like parsley, they act as a group to entangle it. By controlling the amount and the shape of these grains, you can ensure that you always pick up the same amount of something and can even deploy a specific shape and number of grains to pick up a certain object. You can then change these to pick up something else, opening the door to a completely programmable and flexible picking.

These essentially work like a piece of Velcro. Velcro has several small hooks that act as a group to adhere to an object. By changing the shape and number of these hooks you can make Velcro adhere to different surfaces, and we’ve just moved beyond this with computer methods to effectively remove the strap. No other system can as effectively pick up a range of soft and irregular shaped objects.

One of the best things about this approach is that it requires no computer vision. If you were to put camera on a robotic gripper and run an algorithm through it to identify and pick up different objects in real-time, not only would that be incredibly difficult; the materials needed to build the system would be really expensive. Our system lets you operate cheaply and at scale.

What are your hopes for the future?

AF: With our option allowing for significant deployment and scale up, our goal ultimately is commercialisation. Robotic systems on the whole struggle with gripping and picking, and this is a real sea change in how they could revolutionise our supply chains and make them more resilient.

AR: As the system is re-programmable, we would also like to use these robots in scenarios like recycling and waste management. You could in theory have several robotic grippers in place as a conveyer belt of recycling waste passed, each picking up a different kind of rubbish, like plastic bottles or sandwich wrappers. This is work at a fundamental level, which means we have a whole range of applications to explore.