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A robotic dish-scrubber for commercial kitchens

Video of a robotic dishwasher
Video courtesy Dishcraft Robotics

Like an automated carwash for plates, a new commercial-grade robot dish-scrubber takes in dirty dishes in tall stacks and spits clean ones out the other side — potentially cutting dishwashing staffs by more than half.

But, but, but: In a concession to the limitations of today's robots, the machines can only handle specially made plates and bowls with magnetic inserts, and their cost lands them out of reach of all but the biggest restaurants and cafeterias.

Why it matters: Dishwashing, a longstanding entry point for restaurant workers, is an unpleasant and potentially dangerous job. Add in low pay and restaurants face a near-constant churn: The average tenure for dishwashing staff is under a month and a half.

What's happening: The robotic dish-scrubber from Dishcraft Robotics, a Silicon Valley startup, is the latest in a boom in food robotics that we've been covering. It takes the place of the manual scrub most dishes undergo before heading to a commercial dishwasher, which sanitizes them with chemicals or very hot water.

How it works:

  • Restaurant workers stack plates and bowls into carts, sorting items into separate slots. When a cart is full with 70 or so items, it's wheeled into the mouth of the machine.
  • As seen above, a magnetic arm picks up individual dishes and sticks them onto a rotating wheel, which brings them to a scrubber designed specially for Dishcraft's own plates and bowls.
  • After a good scrubbing, the machine's cameras and sensors check for remaining gunk, and scrubs a second time if needed. Finally, clean dishes are racked and sent out the door, to be sent into a sanitizing machine.

The scrubber, by Dishcraft's account, is fast and uses water and energy more efficiently than people. But it's inflexible.

  • Its process is "standardized as much as possible," says Dishcraft cofounder Paul Birkmeyer. That helps file off what roboticists call "edge cases" — unusual scenarios that can trip up machines.
  • To use it, restaurants have to switch to custom bowls and plates. The machine needs the embedded magnets to move them around, and its scrubbing and inspection mechanisms have been built specifically for these dishes.
  • It can't clean cups, glasses and silverware. (Birkmeyer says 90% of dishwashing time is currently spent on plates and bowls.)

Only the biggest kitchens, like hospital or hotel cafeterias serving many hundreds of diners a day, might benefit from the robotic scrubber.

  • Dishcraft won't say how expensive its machines are, but claims they can save big operations money by cutting down on dishwashing staff.
  • They are already deployed in a few big restaurants, and Dishcraft is marketing them to more, backed with its $25 million in venture capital.