The U.S. Department of Transportation is investigating Elon Musk’s brain implant company, Neuralink Corp., after an animal rights group said it obtained emails suggesting the startup did not follow proper procedure when shipping possibly hazardous materials.

Hundreds of well-funded robotics startups are working on self-driving cars, self-piloting drones and shelf-diving warehouse robots. One lesser-known area that’s beginning to draw the attention of investors: autonomous lawn mowers.

Hyperloop Technologies Inc., a Los Angeles-based company building a futuristic transportation system, said it raised $50 million in convertible-debt financing and hired Uber Technologies Inc.’s former chief financial officer.