Momentum Machines/The University of Pennsylvania A secretive robotics startup has raised a new round of venture funding as part of its quest to replace humans with robots in the kitchens of fast-food restaurants.

Momentum Machines secured over $18 million in financing, according to a SEC filing in May. The startup has generated investments from top VC firms Google Ventures and Khosla Ventures in the past.

In 2012, Momentum Machines debuted a robot that could crank out 400 made-to-order hamburgers in an hour. It's fully autonomous, meaning the machine can slice toppings, grill a patty, and assemble and bag a burger without any help from humans.

The company has been working on its first retail location since at least June of last year. There is still no scheduled opening date for the flagship, though it's expected to be located in San Francisco's South of Market neighborhood.

San Franciscans have been warming up to the idea of a restaurant experience with minimal human interactions for years. In 2015, futuristic food-chain Eatsa opened downtown. The vegetarian restaurant, which specializes in quinoa bowls, automates the ordering and pick-up process. It's since expanded to New York and Washington, DC.

In San Francisco, robots also run food deliveries for Yelp's Eat24 and pour coffee at Cafe X. These changes, along with other evidence that AI could displace huge swaths of workers, have even prompted a San Francisco politician to consider a "robot tax" to help offset the economic devastation a robotic workforce might bring.

Although Momentum Machines eliminates the need for line cooks, front-of-house and custodial staff will likely still be required. The company also told Business Insider in 2012 that letting robots fill in for humans in the kitchen may actually promote job growth because the automation would allow the company to hire new employees to continue developing their technology and to staff additional restaurant locations. The full impact of a robot-powered kitchen remains to be seen, however.

A Craigslist job posting from Momentum Machines last summer gave us our first glimpse into what the restaurant might be like.

"The burgers sold at 680 Folsom will be fresh-ground and grilled to order, served on toasted brioche, and accented by an infinitely personalizable variety of fresh produce, seasonings, and sauces," the ad said.