Absolute Length Sensor

Our paper “Absolute length sensor based on time of flight in stretchable optical fibers,” by Ji-Tzuoh Lin and C. K. Harnett, is accepted at IEEE Sensors Letters . What’s new over our previous work? We measured the travel time of a laser pulse, rather than its amplitude in a stretchable optical fiber. This method is less sensitive than amplitude measurements are to manufacturing variations and surface curvature, making it good at measuring lengths over surfaces with varying shapes. Check it out here https://paperpile.com/shared/K8BdV6

Best of McMaster Carr

If you’re building robots in the US you probably order from this catalog. It is time to place an order and I have only one small item in the cart. Can anyone in the lab think of anything they need? (Not sponsored content. Is that even possible?)

5733T83. Traffic light. We need to control traffic flow in the hallway for social distancing. Let’s get one for each end of the building. Think of how many Capstone projects will be launched.

2701T36. The front load cargo tricycle is needed for so many reasons, like 1) Look at it.
No, we are not going to get one. Let’s just enjoy the idea that it exists and can hypothetically get here Wednesday.

Quick Bricks

Remote work got standardized when Chris N. suggested we work with “bricks.” Plastic bricks emerged from boxes and tubs in different cities. He designed some 3D printed parts with pockets for bricks, so he could click them into place on this torque-vs-angle testing platform when the parts arrived from campus. No need to ship the heavy platform, because he also had some of those slab-like bases around.

Lego base for lab experiment

Even now, with students near enough to campus to pick up and drop off items, the bricks are paying off because every photo has a scale bar. Good idea, Chris, one to keep handy for future collaborations at all levels!

Wandering diodes

These micro-MELF diodes are a little over a millimeter tall. Normally they’re arranged in an orderly fashion in a tape, so a robotic pick-and-place system can grab them individually and place them on a printed circuit board. Not today! They spilled out. Is there a way to self assemble them onto a surface? People have been working on that for a while:

Wei Zheng, Jaehoon Chung, and H. O. Jacobs, “Fluidic heterogeneous microsystems assembly and packaging,” J. Microelectromech. Syst., vol. 15, no. 4, pp. 864–870, Aug. 2006.

But the video above shows they are also a little magnetic, and might be put into position using guiding structures. Now if we can get them all facing the same direction…

MicroMELF | 3D CAD Model Library | GrabCAD
Image from https://grabcad.com/library/micromelf-1

Slightly bigger ones, all packed up in tape:

300 Vishay ZM4747A Melf 20V 12.5mA Silicon Planar Zener Diodes ...

(from https://www.amazon.com/Vishay-ZM4747A-12-5mA-Silicon-Planar/dp/B01F2I6SWS)