See where to punch holes easily in a PDMS microfluidic device

Amy Rowat and David Weitz describe how to see where to punch holes in a PDMS microfluidic device.

Amy C. Rowat and David A. Weitz
Dept. of Physics/Harvard School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA

Why is this useful?


The microfluidic channels in PDMS devices are connected to the macroscopic world by inserting tubing into the inlet holes of flow channels.  We make inlet holes by punching through the PDMS with a razor-sharp biopsy punch to remove a piece of PDMS similar in diameter to the tubing.  However, it is often difficult to see where to punch this hole, especially when channels are shallow in height.  Here we present a tip that makes it easy to see where to punch inlets in PDMS devices by putting a ring light source beneath the device; because the channels scatter the light, the inlets are easy to see.

What do I need?


  • PDMS mold
  • biopsy punch (0.75 mm for PE20 tubing, Harris Uni-Core, Ted Pella, Inc., Redding, CA)
  • piece of glass (borosilicate plate or glass microslide)
  • ring light (Dolan-Jenner Industries, Inc.) [Note: many dissecting scopes are equipped with a ring light; a homebuilt apparatus could also be used.]
  • isopropanol

What do I do?


  1. Peel the PDMS off the master wafer.
  2. Invert the ring light and place the glass slide on top.  [We use the light source from the dissecting scope in our cleanroom.]  Then place the PDMS device on the glass slide with the channels facing upwards (Figure 1).  By moving the device to different positions on the glass plate, different angles of backlighting result making it easier to see the inlets and channels.
  3. When you have located the correct position of the inlet, press the biopsy punch through the PDMS so that it contacts the glass, then turn the punch one quarter clockwise.  Lift the PDMS off of the glass surface, the then depress the button on the biopsy punch to release the PDMS plug.  Be sure that the plug detaches from the device; sometimes the plug can get stuck and obstruct the inlet hole.
  4. Rinse the device thoroughly with isopropanol.  Chunks of torn PDMS get stuck in the holes, so it is important to flush them with solvent.  Dry with filtered air.
  5. Plasma treat the PDMS, bond to glass, and insert tubing.

Figure 1. (a) A glass slide placed on top of an inverted ring light creates a platform that makes it easy to see where to punch holes in a PDMS microfluidic device. The device shown here has channels of 4.5 µm height. (b) In the absence of backlighting, the channels are difficult to see. Scale, 5 mm.

What else should I know?


In addition to backlighting, it also helps to fabricate a pattern in or around the inlet that scatters light.  We typically use a pinwheel pattern inside the hole as well as lines radiating out from the holes as shown in Figure 1.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

9 Responses to “See where to punch holes easily in a PDMS microfluidic device”

  1. . They shift family members products of client with protection and shift perfectly. Packers and movers assistance organization execute all the procedure phase wise.

    Expert 5 Packers and Movers Delhi go to
    http://www.expert5th.in/packers-and-movers-delhi/

    Expert 5 Packers and Movers Gurgaon go to
    http://www.expert5th.in/packers-and-movers-gurgaon/

    Expert 5 Packers and Movers Chennai go to
    http://www.expert5th.in/packers-and-movers-chennai/

    Top 6 Packers and Movers Pune go to
    http://packersmoverspune.top3rd.in/

    Expert 5 Packers and Movers Hyderabad go to
    http://www.expert5th.in/packers-and-movers-hyderabad/

    Expert 5 Packers and Movers Bangalore go to
    http://www.expert5th.in/packers-and-movers-bangalore/

    Expert 5 Packers and Movers Mumbai go to
    http://www.expert5th.in/packers-and-movers-mumbai/

  2. finished up, experienced plus more essentially efficient.
    Packers and Movers in Bangalore @ http://www.expert5th.in/packers-and-movers-bangalore/
    Packers and Movers in Delhi @ http://www.expert5th.in/packers-and-movers-delhi/
    Packers and Movers Gurgaon @ http://www.expert5th.in/packers-and-movers-gurgaon/

  3. I’m hoping recommendations moreover to concepts talked about in this post will allow you to choose the right movers in your position.
    Packers and Movers Chennai @ http://www.expert5th.in/packers-and-movers-chennai/
    Packers and Movers Noida @ http://www.expert5th.in/packers-and-movers-noida/

  4. For those who have definitely not too much aspects consequently it truly is without query you will need to pay much less.
    Movers and Packers in Mumbai
    Movers and Packers in Hyderabad

  5. outstanding top great top great top great top high quality of aspects you should choice and also move for your clean position.
    Packers and Movers in Pune
    Packers and Movers in Bangalore

  6. Thanks for sharing your info. I really appreciate your efforts and I will be waiting for your further write
    Packers and Movers in Hyderabad
    Packers and Movers in Bangalore
    Packers and Movers in Mumbai

  7. Thanks for sharing. I hope it will be helpful for too many people that are searching for this topic-

    Packers and Movers in Chennai
    Packers and Movers in Pune
    Packers and Movers in Delhi
    Packers and Movers in Gurgaon

  8. juki says:

    Catering Jakarta Konsultan Pajak Jasa Pemasaran Rental Mobil Video Editing Jasa Konsultan Pajak Sewa Mobil Jakarta http://birojasa.xyz Jasa Pemasaran Online Snack Box http://jasatraining.xyz Jasa Akuntansi Promosi Bisnis Online http://kursusonline.xyz Rental Mobil Jakarta Jasa Konsultasi Pemasaran Paket Pernikahan Jasa Video Shooting
    Catering Jakarta Konsultan Pajak Jasa Pemasaran Rental Mobil Video Editing Jasa Konsultan Pajak Sewa Mobil Jakarta http://birojasa.xyz Jasa Pemasaran Online Snack Box http://jasatraining.xyz Jasa Akuntansi Promosi Bisnis Online http://kursusonline.xyz Rental Mobil Jakarta Jasa Konsultasi Pemasaran Paket Pernikahan Jasa Video Shooting
    Rent Catering Info Konten Information Travel Marketing Jual Rumah Informasi Training Jasa Jual Beli Marketing Rumah Jasa Catering jasa training Jasa Akuntansi Little Forum Kursus Online Rental Mobil di Jakarta Lomba SEO Rumah Tangerang Jasa Company Profile
    canhr.info theregenerationroadmap.info youthalive.info
    produk kecantikan khasiat cream alami krim pemutih prdouk wajah unggulan krim pemutih ketiak produk kecantikan kosmetik wajah aman produk kecantikan wajah krim pemutih wajah herbal pemutih kulit badan krim pemutih jual baju wanita jual baju import grosir pakaian wanita grosi baju korea tas import branded butik tas online tas branded Jual Rumah Rumah Alam Sutera Rumah Dijual Alam Sutera Rumah Bintaro Rumah Dijual Bintaro Rumah BSD Rumah Dijual BSD Rumah Gading Serpong Rumah Dijual Gading Serpong Jual Apartemen jual apartemen aceh langsa jual apartemen bali badung jual apartemen bali denpasar jual apartemen kota cilegon jual apartemen banten serang jual apartemen tangerang jual apartemen alam sutera jual apartemen bsd tangerang jual rumah jual rumah banten jual rumah kota cilegon jual rumah serang jual rumah tangerang
    jual rumah tangerang alam sutera jual rumah tangerang bsd jual rumah tangerang gading serpong Jasa Bangun Rumah jasa bangun rumah jasa desain jasa desain arsitektur jasa desain furniture agen properti jual beli rumah jasa konsultasi properti jasa kontraktor jasa kontraktor contblock jasa kontraktor cor hotmix jasa kontraktor drainase jasa kontraktor instalasi listrik jual seragam kaos konveksi baju jual kostum bola sablon polyflex jual baju online
    Video Jasa Rumah Bangunan Jasa Arsitek Jasa Desain Interior Jual Paving Block Jual Pasir Jual Bata
    Biro Jasa Jasa Pemasaran pelatihan karyawan jasa akuntansi biro jasa perijinan Rental Mobil Jakarta Jasa Catering Jasa Video Shooting

Leave a Reply

*