Mobile robot vendor Fetch Robotics Inc. said today it had raised $25 million in venture capital funding to expand its warehouse automation product line designed to help customers meet surging warehouse labor demand caused by the fast growth of e-commerce.

The investment came mostly from Sway Ventures, with additional participation from previous Fetch investors O'Reilly AlphaTech Ventures, Shasta Ventures, and Softbank's SB Group US. It follows earlier investment rounds of $3 million and $20 million for Fetch, bringing the three-year-old company's total funding to date to $48 million.

San Jose, Calif.-based Fetch makes autonomous material handling vehicles for commercial and industrial environments. Its products include the Freight100, Freight500, and Freight1500 models of its autonomous mobile robot (AMR) design, supported by the firm's cloud-based FetchCore software program.

Named for their carrying capacities measured in kilograms, the warehouse robots can automate the delivery of loads weighing up to 220 pounds, 1,100 pounds, or 3,300 pounds respectively. The square, squat, 14-inch-tall bots range from two by two feet to four by four feet and look similar to warehouse robotics products from Amazon Robotics or and look similar to warehouse robotics products from Amazon Robotics or Otto Motors. Fetch says its robots fill a different niche than comparable platforms because they can work alongside humans and can use an array of sensors to collect data as well as handle inventory.

Fetch plans to use its new funding to expand its product development, sales operations, and commercialization efforts, Fetch Robotics CEO Melonee Wise said in a phone interview. The company plans to increase the range of sensors carried on its robots, such as Fetch's latest product, a radio frequency identification (RFID)-enabled bot that is used for inventory cycle counts and for locating individual goods in a warehouse, she said. Fetch will also continue improvements to the data-analytics capabilities of its FetchCore fleet management system software, said Wise.

By providing a range of robots with different capabilities, Fetch allows customers such as German transport and logistics firm Deutsche Post DHL Group and third-party logistics provider (3PL) RK Logistics Group to use a single robotics provider to manage the varied tasks and workflows needed in a busy distribution center, Wise said.

The investment in Fetch is the latest in a flood of funding directed at providers of warehouse robotics and material handling automation, including the announcement last month that warehouse automation vendor Locus Robotics Inc. had raised $25 million in venture capital and planned to drive sales of its e-commerce fulfillment robots in China and Japan.

Investors say that trend is justified by the steep growth of e-commerce and rising demand for warehousing services. "The warehouse and logistics automation market is estimated at over $40 billion today, and is poised to double over the next five years," Brian Nugent, founding general partner at Sway Ventures, said in a statement. "Our investment in Fetch complements and extends our portfolio of ... leaders who are transforming the global supply chain."