Stephen TranovichSpeaking of which, let's get this Hack Chat started! A BIG welcome to @Amitabh Shrivastava for joining us on today's chat. Why don't you start us off by telling us a little about yourself?
Welcome @Amitabh Shrivastava ! :-)
Thanks @Boian Mitov! By the way, love your acoustic levitation project!!
Thank you @Amitabh Shrivastava :-)
Aight
So, I'm a grad student at ITP, NYU
I like to make stuff, electronics, fabrication..
I studied physics and biology in undergrad, but quickly realized that I prefer just making things
So I became the engineering consultant for the ecology department
Made a windtunnel, and a sensor for measuring elephant height
Then moved to startups and worked on wearable gaming
Now, at NYU I'm working on embedding sensors in concrete and soft robotics!
I really enjoy making tools that others can use to make cool stuff
Very cool!
Shall I speak a bit about Programmable-Air?
We already have some great questions from the community, especially @Jarrett , so let's get started!
Sure!!
Let's do a few community questions then dive into programmable air. I'm really excited to hear about it.
First question(s) from @Jarrett : What kind of pumps do you like to use?
Have any preference for small / lightweight / cheap ones?
Yeah that's a great question
In pneumatics, as in all of engineering there's tradeoffs with size, cost and quality
I wanted to go for something that can generate pressures in the range that humans can generate with their mouth and about the same flow rate
After a lot of testing I settled on these pumps:
https://www.amazon.com/gp/product/B01MR3JZZF/ref=ox_sc_act_title_4?smid=A3BG62S1F23IH5&psc=1
DC12V micro air pump Electric pumps mini vacuum pump pumping Booster For Medical
Micro air pump Electric pumps mini vacuum pump pumping Booster For Medical Rated voltage: DC12V Rated current: Air flow without load: 3.2LPM Max. vacuum: Noise: Life test: >500 Hours Note: Welcome to wholesale ...,we offer you more competitive wholesale price . Package included: 1 pc Micro air pump
Similar pumps are available for 5$ a pop and they can do 2L/min flow rate and + - 8 PSI
If you don't know what you need, these are a good place to start
*end rant*
hah!
Let's round out that series of questions with their next one: Realistically, how much weight do you expect small portable pumps to be able to lift?
Hmm, it really depends on the actuator attached to the pump
Let's look at the math
You can generate -8 PSI
So, if you have a one square inch surface area, you can lift 8 pounds.
I can totally imagine lifting 100 pounds with this pump with a good o-ring seal
Have you considered small cans of compressed air (like airsoft cannisters)?
If so, how would controlling airflow work?
Hmm, so compressed air cans are much higher pressure range
I think they are around 50PSI
or even higher
The valve I use can't handle those pressures
But It's totally possible to control the air flow with better valves
I'd point you to the Harvard Soft Robotics toolkit
https://softroboticstoolkit.com/book/control-board
Fluidic Control Board
The Soft Robotics Toolkit Control Board is an open source hardware platform that can be used to operate and control fluidic soft actuators, such as the PneuNets Bending Actuator or the Fiber-Reinforced Actuators described on this site.
Read this on Softroboticstoolkit
http://content.smcetech.com/pdf/VQ_3Pt.pdf
^ these valve will control air can flow rate with no issues
So let's talk more about Programmable-Air! Tell us, what made you want to create this project?
So, I took a class on Soft Robotics with Kari Love, here at ITP
And I was soo excited to make a walking silicone soft robot
Something like this:
https://www.youtube.com/watch?v=2DsbS9cMOAE
And everyone around me was making stuff like this, because it's just a 3D printed mold and some silicone
But then, they were controlling these robots by blowing air with their mouth or like a blood pressure cuff pump
So cool and freaky!
I was like
You guys!! that's not how you control a robot
I looked around, and I couldn't find any cheap way to control soft robots.
So I decided to build one.
Brilliant. Tell us more about the design process. Where did you start?
I started with the two projects that were already out there
The harvard soft robotics toolkit, and pneuduino from MIT
They were both designed for use by researchers, so they used expensive equipment
I started out looking for cheaper replacements for each component: the pumps, the valves and the pressure sensor
I just ordered a bunch of stuff and started playing around
I would have start by taking Limbo Dance classes
:o)
Haha
It's totally a limbo
The thing with pneumatics that makes it annoying is that you have not only the current and voltage compatibility but also the flow rate, the pressure range and nozzle size
You have a valve that's the perfect size, cheap, the right flow rate and voltage
And then you realize it doesn't support vaccum
So, it was a lot of trial and error
What were your target parameters?
Broadly, I wanted to blow up a balloon in under a minute, I wanted it to generate slightly more pressure than possible with the human mouth, the board had to be under 4"x4" and the power had to be under 10 watts
And importantly, it had to be under 100$
Which is like the impulse buy range for me
I was not thinking of it as a product, back then though
When did you decide it should be a product?
Hmm, I think it was when I presented it for the first time in my class
Suddenly everyone wanted to work with me and use it to control their projects
Which was great! They could make the cool soft robots and I'd just help them control it
^ A friend made this for her class project
cooool
That was when I realized the potential of this as a product
That's so cool! I think this is a good lead-in to another community question from @anfractuosity : Have you seen this - I'm wondering if you may have an idea how that works?
Yeah, I friend of mine made something similar, and it's actually a perfect example of what's possible with Programmable-Air
There are three air tubes inside the actuator
arranged symmetrically around the center
When you put air pressure in one of the tubes, it expands
And the whole actuator bends in the direction away from the tube
ooh, do you have a video or anything on your one?
By putting different pressures in each tube, you can control which direction the actuator bends in and y how much
@anfractuosity I've just messaged my friend, let's see if he responds in time
cheers!
dumb question you mean there's multiple air tubes, with dead ends right
yes
cool, thanks
lemme see if I can find an explainer gif or something
The next community question if from me! Does Programmable Air give you the ability to control the speed at which air is pumped? If so, between what ranges can you control it?
@anfractuosity something like this: https://en.wikipedia.org/wiki/Stewart_platform
But with air
@Stephen Tranovich Yes! by controlling the PWM signal to the motors
And by controlling the nozzle size of the tubing, but that can't be changed programmatically
You can go anywhere from 0 to 2Litres per min
There's two pumps, so if you use them both to pump air out you can get up to 4 litres per minute
Actually, really low flow rate is annoying because the motors tend to stall
But, you can always have a slightly higher flow rate on the motor and the switch the valve on and off
What applications do you want to see programmable air used for?
I don't know Stephen. And that's the whole point!!
I can see application in assistive tech, art and design world
Wearables, underwater stuff, some hydraulics
But really, I want people to start thinking of pneumatics as an option when thinking of new projects
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