IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Applied Surface Analysis Wednesday Sessions
       Session AS-WeM

Paper AS-WeM9
A Surface Chemistry Study of Laser Ablated Polymers Used for Microfluidic Devices

Wednesday, October 31, 2001, 11:00 am, Room 134

Session: Biomaterials and Polymers
Presenter: D.L. Pugmire, National Institute of Standards and Technology
Authors: D.L. Pugmire, National Institute of Standards and Technology
E.A. Waddell, National Institute of Standards and Technology
C.J. Taylor, National Institute of Standards and Technology
L.E. Locascio, National Institute of Standards and Technology
M.J. Tarlov, National Institute of Standards and Technology
Correspondent: Click to Email
Polymer substrates are being investigated for use in microfluidic devices because of their low cost, ease of fabrication, and wide range of materials properties. It is well established that the surface chemistry of a plastic substrate greatly influences the electroosmotic flow (EOF) behavior of microfluidic channels made from that material. Typical channel imprinting techniques do not offer direct control of surface chemistry. Laser ablation shows promise as a versatile method for directly forming a variety of microchannel geometries in plastics. In addition, we have demonstrated that surface chemistry, and, therefore, EOF behavior can be controlled by changing the atmosphere under which laser ablation of the plastic is performed. The surfaces of several plastics ablated in a variety of environments were studied with x-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared spectroscopy (ATR-IR), and scanning electron microscopy (SEM). XPS results indicate that laser ablation generally resulted in an increase in the oxygen content of the polymers studied, regardless of ablation atmosphere. However, this oxygen uptake was often more pronounced when ablation was performed under O@sub 2@ as opposed to N@sub 2@ or Ar. Ablation of commercially obtained PVC, with an organotin stabilizer, resulted in concentration of tin species at the ablated surface. These results will be discussed and compared to EOF rates of ablated microchannels.