Valve pins. The front view of the device in action wherein the punch card tape reels in towards the observer upon actuation. The image focus is on the valve pins that get actuated whenever there is a punched hole in the card. Presence of the holes results in gear teeth plucking the cantilever beams on which valve pins project perpendicularly. This action leads to a downward and forward motion of the valve pins. The net downward movement results in the opening of the valve for the duration of the actuation (~0.5 s). The capture and playback rate for the movie is 60 frames per second.
Korir G, Prakash M
CC BY 4.0
<a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349784/bin/pone.0115993.s008.mp4">S1 Movie</a> from <cite style="font-style:normal">Korir G, Prakash M (2015). "<a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349784">Punch Card Programmable Microfluidics</a>". <i>PLOS ONE</i>. <a href="https://en.wikipedia.org/wiki/Digital_object_identifier" class="extiw" title="w:Digital object identifier">DOI</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1371/journal.pone.0115993">10.1371/journal.pone.0115993</a>. <a href="https://en.wikipedia.org/wiki/PMID" class="extiw" title="w:PMID">PMID</a> <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pubmed/25738834">25738834</a>. <a href="https://en.wikipedia.org/wiki/PubMed_Central" class="extiw" title="w:PubMed Central">PMC</a>: <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349784">4349784</a>.</cite>