Lots of cool stuff in the hardware AI space

https://sambanova.ai/ - Enterprise AI and dataflow-as-a-service for established moodels

https://www.cerebras.net/ - AI accelerator, trying to compete with NVidia

https://www.graphcore.ai/ - Another AI accelerator company - UK based

https://femtosense.ai/ - Sparse NNs on very low power chips - cool hardware and software challenges

https://sima.ai/ - ML accelerators for embedded applications

https://ambiq.com/ - Not AI, but low power chips for wireless using some fancy tech that reduces energy leakage

There are dozens more, these are just the ones I've heard of.