3 ms·
"When heated in an oven or with a heat gun, the plastic shrinks by about 5/8ths and becomes thicker and more rigid, while retaining the colored design." http:/
by aarongough 17y ago
"When heated in an oven or with a heat gun, the plastic shrinks by about 5/8ths and becomes thicker and more rigid, while retaining the colored design."
http://en.wikipedia.org/wiki/Shrinky_Dinks http://en.wikipedia.org/wiki/Shrinky_Dinks
Seems like you would be able to get pretty small feature sizes if you had a really high resolution printer to begin with...
- regularfry 17y agoIt surprises me that 5/8ths is enough of a difference to be useful, but then I guess it's the way it bunches and forms a ridge that's important for the microfluidics, not the absolute feature size. Hm.
- aarongough 17y agoIt didn't strike me that 5/8ths wasn't actually a huge amount until I thought about it. If the ability to form troughs/ridges is the important thing then I think that the PCB etch/make mold technique would be just as useful. But I'm not sure what the smallest feature size is that you can make with this method: PCB etch/make mold method: Laser-print an inverse pattern mask on clear plastic film Expose a UV sensitive photoresist PCB using the mask Etch the PCB Make a polymer mold (or mold the final part) using the troughs/ridges formed by the etched/unetched copper on the PCB I know this method has been used for replicating fingerprint patterns in the past (Mythbusters!) and I remember hearing it being used for a few other things...