Visualizing microdroplets in action with foldscope

Shout out to Saad for introducing me to foldscope on my last day of summer internship at Stanford. Every now and then, I carry foldscope in my backpack in case I see something interesting and want to check it out. A couple of weeks ago, I forgot to sign up for microscope in lab, and as a consequence, I wasn’t able to run experiment. Luckily, foldscope came to rescue and kept me busy. Since reading Professor Prakash’s post on reflection mode, I’ve always wanted to try it out. So, I attempted to make a quick simple oil water microdroplets to see if I can visualize them. Turned out I can with foldscope using high-speed camera on my phone. Indeed, it did blow my mind.




8 Comments Add yours

  1. Saad bhamla says:

    Very resourceful of you, Chew!
    You should share a picture of your setup as well with the community.

    And welcome to microcosmos : )

  2. Manu Prakash says:

    Beautiful. I know several people have mentioned starting to do microfluidics with Foldscope; but this is indeed the first clear post. What frame rate did you collect this data.

    Welcome to the Microcosmos community.


  3. chewc12 says:

    @ Manu, it was captured with 240.

  4. Manu Prakash says:

    @Chew: Nice – it’s incredibly fast 🙂 even at that frame rate; it appears real time.

    People in the community would love to see a picture of the setup. How was the chip mounted. Where is the illumination/what kind? Where does the tubing go etc etc. I am sure people would love to replicate this in corners around the world.


  5. chewc12 says:

    @ Saad: Just include the setup.

    @ Manu: yea, it was incredibly fast, I slowed the speed of my video down quite a bit in video editor. But I think 120 should be enough to capture if the flow rate is slower. I just use the flashlight from the phone by punching an extra hole like you mention in your post. I had trouble focusing but I was able to get a few seconds of footage. Hope this is helpful.

  6. Paul Joseph says:

    How did you fix the focus on the foldscope ?
    did you just tape it down ?

  7. chewc12 says:

    @ Paul, yes. I put a small double-sided tape on the edges of the chip to keep things in place.

  8. damontighe says:

    super cool

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