When you see robots that can pick up, move, and place objects in new spots – in a warehouse or factory, for example – chances are you are looking at a delta robot. Also referred to as a parallel or picker robot, these machines tend to replace humans in the fields of manufacturing, assembly, and packaging because they are often more precise while moving at a more rapid pace.
While these robots tend to be highly functional and worth the one-time investment of their cost, they can also be relatively large. Now, a researcher working in Robert Wood’s Harvard-based Microrobotics Lab, Hayley McClintock, has led a team in scaling down the delta robot to produce a mini-delta that is, in a word, impressive. The milliDelta, as it’s been dubbed, is one of the quickest, most precise picker robots seen to date.
When compared to other kinds of robots with interlocking parts and joints which require a series of heavier, decentralized motors, delta robots can maintain higher speeds and precision because they rely on stationary motors. Instead of the sources of power being extended away from the machine’s base as in other forms, a delta’s motors are all positioned at the base of the structure, which is comprised of three parallel parts (hence, the delta). As is apparent, this allows for versatility of function and speed of movement that robots with heavier arms simply are not capable of.
While the original design is the brainchild of Reymond Clevel, McClintock and the Harvard team took that 40’s-era design, scaled it down, and ran with it. The Harvard milliDelta’s 15 mm. x 15 mm. x 20 mm. frame weighs only 430 milligrams, with a payload capacity (1.3 grams) that is greater than its own weight. As the video demonstrations show, its maximum 75 Hz speed still provides precise motion, a testament to the parallel robot’s design and the Harvard team’s ingenuity.
Currently available Delta robots are only able to operate at a few hertz, McClintock said. So for our robot to be able to draw circles at frequencies up to 75 Hz is quite impressive.
The milliDelta’s piezoelectric actuators are stimulated into action by an applied voltage. The individual parts are made from a combination of carbon fiber, Kapton film, and adhesive. Though the team used the laser-micromachine method to bring the milliDelta prototype to life, they believe eventually a more efficient manner of pop-up fabrication could allow for scalable production.
As far as uses, the team envisions relatively tedious, small-scale tasks such as the assembly of circuit boards and small robots. If the specifics can be figured out, they even believe that the milliDelta may have a down-the-line application in assisting surgeons with sensitive tasks in the operating room.