Great! Really enjoyed that, thanks
Show HN: I made a new sensor out of 3D printer filament for my PhD
121–130 of 138 posts
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#122very clever idea!
if you know how OTDR works, location is known by high speed modulation and high speed sampling components, which means high costs, if you want to achieve higher resolution. Usually the laser pusle will be in the level of nano seconds.
what's being introduced in the article is using multiple fibers with coded location info. therefore no need to have sophisticated OTDRA-like equipment to get the location info.
not sure if my understanding is right, but good job: from a simple idea to sophisticated design, optimization and even commercialization.congrats.
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#123It seems to me that the refractive index plays a role: couldn't you increase resolution by replacing air by another medium every other cut? Say air, water, air, etc. My reasoning is that you'd increase the resolution without adding too much technical complexity. My maths is too rusty to evaluate how it would mess with the gray code though. Very nice idea
I didn't include this in my article but I did some experiments early on (for a different idea) with air bubbles in oil inside a Teflon coated tube but that presented a lot of challenges (mainly the bubble breaking up) that made it not ideal for something like this.
This can certainly be miniaturized with the right manufacturing techniques but I left that for the future.
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#124This is awesome! Presumably you can make this work with any interface that doesn't enforce the total internal reflectivity of a fiber optic cable, and therefore allows light to leak out. Instead of an air gap, have you tried experimenting with removing the cladding of the fiber optic cable, but keeping the core intact? Alteratively, could you use a short segment of colored cladding that allows certain wavelengths to…
I did experiment with various ways of allowing light to escape but nothing came close to the properties of a total air gap. You can actually measure (relative) bend angle with it like a protractor since the attenuation is very linear!
There is already existing work that uses colored segments for something similar but those techniques are hard to do outside a well equipped lab.
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#125Very cool! I used to build sensors similar in construction, but in all glass. Was a great challenge and a lot of fun. I like your spin on things. Well done completing the Phd!
Thanks!
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#126Could you get a similar effect by cutting dimples or notches in patterns (like a helical line of small conical holes) along the whole length in a sleeve instead of using separate pieces and infer overall curve shape? Or do the segments need to be cut completely through?
Yes!
The catch is any notch you make will weaken the material significantly and you'll have fatigue failures. That's the sneaky part of using a flexible sleeve, you don't introduce any undesired weaknesses.
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#127is the idea to eventually make muscle fibers with lots of these stranded together?
No I actually didn't have muscle fibers in mind -- there's quite a bit of ongoing research specifically in that area.
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#128How does it work if there is more than one bend? Is it able to localize both bends? And what about the bend directionality? Anyway nice project. I could see it being used for a mesh to give robots a tactile skin covering.
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#129Awesome work. Would be cool to make a really long one and tape it all along the links of an industrial robot arm and see if you can train a neural net to predict the location of the end effector (which you would already know precisely from the angles of the linkages) from the readings of your sensor.
Re: Show HN: I made a new sensor out of 3D printer filament for my PhD
#130This is cool as hell! I hope your PhD continues well, and that this invention serves you in the future. Do you put any lube on the interface between the silicone sleeve and optical cable? I imagine the bending action will cause displacement, and friction there could rub and/or cause the nominal position to shift around.
Since the sleeve is a stretchy rubber as long as the inner diameter of it is a bit smaller than the outer diameter of the fiber it holds just fine. For more dynamic applications, though, a silicone adhesive, or even super glue for more permanent strands, helps!
Oh cool, that kind of robustness is not what I was expecting. Very cool project!