Rethink Robotics, the Boston-based maker of the Baxter and Sawyer robots founded by iRobot co-founder Rodney Brooks, raised an additional $18 million in an unfinished $33 million Series E round led by private equity firm Adveq. 

Previous investors who also participated in the round included Jeff Bezos' Bezos Expeditions, CRV, Highland Capital Partners, Goldman Sachs and GE Ventures.

This brings cummulative funding to $131.5 million. The new funding will be used for Rethink's global expansion initiatives, as well as new product development.

Scott Eckert, President and CEO of Rethink said:

As we did previously with our Series D round, we expect two closings for different investors. $18M was the initial closing and we will announce additional financing when the transactions are complete.

Sawyer is outselling Baxter ten to one, and we tripled our revenue in 2016. In China, the appetite for Sawyer has been quite high. We’ve sold a large quantity of Sawyer robots. In addition, we are looking to 2017 to be a big year for our deployments in Europe, as we expect to have additional distribution agreements in place in that region soon, as well.