What this post is about:

• Why is robotics so interesting? Is there anything like a 'why now' for robotics?
• What are the leading AI models in robotics? How do they compare, and which one is the best? (ACT, Gr00t, Pi0)
• What are the key challenges in building a robot? (Actuators, inverse kinematics, flow control)
• What are your options for hardware? Do you need to build it yourself or can you just buy it? If so, what are the big brands?
• What are the big robotics companies? What do the top 100 robotics start-ups (by funding in the last 5 years) do? Which ones do I find most interesting and why?

What is the 'Why now' for robotics?

• Low cost for actuators and sensors? Aloha paper says low-cost is 20.000€, SO-100 is 200€

Hardware

• Places to buy a robotic arm:

Company	Robot name	Price	Comment
Robco			Subscription-based
Agilex
Universal Robots
Franka
FANUC
Standard Bots
Kawasaki Robotics
...
...
...

Landmark papers:

• RT-1 (Dec. 2022), which was followed up with RT-2 (Jul. 2023)
• Aloha (Apr. 2023). This paper introduced the ACT method. Also, there's the Mobile Aloha paper for a similar robot on wheels.
• OpenVLA (Jun. 2024) - an open-source
• Octo - An open-source 93m param model
• Pi0 (Oct. 2024)
• Gr00t (Mar. 2025)
• Pi0.5 (Apr. 2025),

Interesting people to follow

• Remi Cadene - AI for Robotics at Hugging Face, leading the development of LeRobot. Also organises robotics hackathons from time to time.
• Igor Kulakov - Built a 300$ arm stronger than Hugging Face's SO-100. Here's a short demo. He also did a cool post comparing Pi0, Gr00t and ACT.
• Alexander Koch (Tau Robotics): Z Fellow working on building general AI for robots. Has a lot of cool demos on his X account.
• Pierre-Louis Soulié

The 'big' robotics start-ups

Company	Based in	Founded	Total funding	What they do	Comment
Physical Intelligence	🇺🇸 SF	2024	$470m	They are working on general-purpose cross-embodiment foundation models. Founded by Chelsea Finn and Sergey Levine, two robotics OGs.
1X	🇳🇴 Moss (but most roles on website are Palo Alto based)	2014	$136m	AI and robotics company developing safe, advanced humanoid androids (like EVE and NEO) to augment the workforce and address labor shortages.
Figure	🇺🇸 SF	2022	$854m	US-based robotics startup focused on developing general-purpose humanoid robots for commercial applications.
DeepRobotics	🇨🇳 Hangzhou	2021	Unknown	Specializes in R&D of quadruped robots, such as the "Jueying" series, for industrial and commercial uses.
Unitree	🇨🇳 Hangzhou	2016	$192m	Only company already selling humanoids; also known for affordable quadruped robots for consumers and researchers.
Skild.ai	🇺🇸 Pittsburgh	2023	$300m	US robotics company working on AI-driven robotics solutions (specifics not detailed in the provided context).
Boston Dynamics	🇺🇸 Waltham, MA	1991	$37m	Legendary robotics company known for advanced quadruped and humanoid robots like Spot and Atlas.	Acquired by Google in 2013, then SoftBank in 2017, then Hyundai for $1.1B in 2021.

Feedback? Anything I'm missing? Send me an email to dominique.c.a.paul@gmail.com