Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am following up on last week’s post, covering my brief corrispondance with Artimus Robotics. Let’s get started!
I first approached Artimus through their site’s Contact Us page [1], where I provided some details about my project – a quadrupedal robot system aimed at hobbyists.
Sticker Shock
The next day, I received an email from Andrew Morton representing Artimus. “Our actuators start at $2,995 and it is another $1,995 for the rest of the kit (kit total starts at $4,990) [2].” He then directed me to the Application Assistant where I could provide more details about my application.
Ouch. I thought HASEL actuators were supposed to be made from relatively low-cost materials. But yeah, I understand: they have the research to pay for, they’re making everything to order, and it’s going to be more durable than something I assemble at home; and that’s just the costs I know about.
Lower Speccs
HASEL actuators reportedly compare relatively well to human skeletal muscle on several metrics [3]. I don’t need that level of performance. I’m also looking at potentially several dozen tiny muscles that only need a few pounds of pulling force. While it would be nice to see my robot galloping, jumping, and dancing, I’ll settle for standing up and walking around obsticles. Getting up and down stairs will be a luxury to strive for.
In all reality, I won’t need my eventual full strength actuators (I’m just going to call them muscles or artificial muscles for the remainder of this post) the moment I have my first fully assembled prototype – certanly not until I have the kinematics worked out. On the other hand, it’s not a bad idea to buy what you’ll need near the end with the idea that you’re not blowing money on as much intermediary equipment.
I went ahead and went through the Application Assistant. The form asked several important questions. What motion does my proposed actuator make? How much, hard, and fast does it move? How long should it last? What kind of space will it be installed in? How presicely controlled does it need to be? Will it need to be self-sensing? What are the most important characteristics you’re controlling for [1]? I answered as best I could, but I found myself leaving the form mostly blank or full of “TBD.”
I came to the last page where it asks for an overall description. I will also take this moment to note that I did not retain a copy of my exact wording, and none was ever echoed back to me. (If there’s one complaint I have with my experience, that would be it). I found myself weaving in most of the information I had put in different note fields, so I compiled it here and tidyed up on the other pages. I also expressed my concern at the up front cost, asking if they offered something like a junior developer’s kit for small scale projects.
Important Questions Without Answers
Hi [Shadow],
Thank you for providing the application details. Do you have a force or stroke specification for the actuators? These are the primary specs used to size an actuator. No problem if you don't have those yet as you're welcome to purchase a standard actuator development kit for preliminary testing to better understand the technology and your needs. I think that is the best path given the complexity of your project.
We don't have any lower-budget actuators, just our standard actuators that start at $2995 or $4990 for the development kit. Please let me know if you would like a formal quote.
Thank you,
Andrew Morton [1]
At this point, I was coming to terms with the realization that Artimus will be out of my price range until I’m much deeper into prototyping. Even then, I may have a tough time keeping my unnofficial $5,000 goal unless the price comes down.
My reply ballparked my figures: a 20 inch robot, muscles ranging 1-4 inches long, 5-10 pounds of pulling force each, and the whole unit anywhere between 5-20 pounds [4]. Total guesswork on my part. But the focus was more on how my pockets weren’t that deep. I thanked Andrew for his time.
I still hope to work with Artimus in the future, even if it’s for my scaled up version.
Andrew got back to me in a third and final email, probably saving face as much as I was. As I suspected, they’re oriented around industrial clients right now, and smaller clients will be served well once economy of scale kicks in [1].
Takeaway
Going forward, it looks like homemade muscles will dominate my development process until I’m ready for something professionally assembled; my first prototypes may very well end up being powered by pneumatics. They won’t be untethered, but at least I can find the figures I need and get back in touch with Artimus when I’m ready.
Final Question
What artificial muscle technology would you recommend as an analogue for HASEL?
Works Cited
[1] Artimus Robotics. Accessed: June 29, 2021. Available: https://www.artimusrobotics.com.
[2] A. Morton. “Artimus Robotics Actuators” Personal emails (June 30-July 2, 2021).
[3] P. Rothemund, N. Kellaris, S. Mitchell, E. Acome, and C. Keplinger “HASEL Artificial Muscles for a New Generation of Lifelike Robots—Recent Progress and Future Opportunities” Nov. 2020 Advanced Materials vol. 33, issue 19, May 13, 2021 Available: https://onlinelibrary.wiley.com/doi/10.1002/adma.202003375. [Accessed: June 6, 2021]
[4] S. 8472. “Re: Artimus Robotics Actuators” Personal email (July 1, 2021)