British robotics startup Starship Technologies is using a $17.2 million venture capital injection to expand the U.S. trials of its self-driving parcel-delivery robots to new cities, the firm said Wednesday.

The funding will come from a consortium led by Mercedes-Benz Vans, and will include firms such as Shasta Ventures, Matrix Partners, ZX Ventures, Morpheus Ventures, Grishin Robotics, Playfair Capital, among others.

Starship will use the funds to refine and expand the use of its autonomous vehicles, which resemble six-wheeled, electric picnic coolers, COO Allan Martinson said in an interview. In its new round of tests, Starship robots will work with the last-mile delivery services DoorDash, for service in Redwood City, Calif., and Postmates, for service in Washington, D.C. These two companies currently provide local package and food delivery with fleets of human couriers, but are now testing the robots as well in an effort to provide faster, cheaper delivery.

Created by two founders of the Internet telephony pioneer Skype, Starship has previously dispatched its robots on extensive test runs in Europe and the U.S. One client has used the robots to deliver donuts in San Francisco. Each robot, which has a maximum capacity of 20 pounds and a top speed of 4 mph, relies on suites of sensors to scoot along sidewalks and cross crosswalks. To date, Starship robots have covered over 16,000 miles during trials in 16 countries and 59 cities as the company continues to refine its technology, Martinson said.

Restaurants or other delivery partners use Starship bots to make deliveries by hailing one robot from a nearby fleet when they receive a customer order. Meanwhile, the consumer uses a smartphone app to track the delivery's progress and receive a code that opens the locked lid to the cargo compartment upon arrival, he said.

"We have done our work," Martinson said. "We have built the robots, designed the mapping, gotten permits from city government, and performed test drives." Martinson said the company plans to add functionality to the robots, and is working with local officials to win permits to drive the robots in additional cities.