Plasma Treatment for PDMS bonding, Glass Slides, Lab-on-a-chip, and Other Microfluidics Applications

Typical applications

  • PDMS bonding with glass or silicon
  • Remove organic contaminations
  • Sterilize surface
  • Generate hydroxyl and carboxyl surface moieties
  • Increase surface hydrophilicity
Plasma treatment for glass slides and coverslip

Related products

Tergeo Plasma Cleaner for PDMS/glass bonding
Tergeo Plus Plasma Cleaner for microfluidics and lab-on-a-chip device cleaning

Tergeo and Tergeo-plus tabletop plasma cleaner

Microchannels have emerged as powerful tools for various biomedical applications. Control of surface properties is very important in high-performance microfluidic devices. Polydimethylsiloxane (PDMS) is one of the most widely used silicone-based polymers in microfluidics because of its low cost, ease of fabrication, bio-compatibility, and optical transparency. However, PDMS is intrinsically hydrophobic. Microfluidics device usually requires the microchannels to be hydrophilic. Oxygen, argon, nitrogen, and ammonia gases have been used to treat the surface of microfluidics and other biomedical devices in order to clean and sterilize the components, make the surface hydrophilic and improve bonding strength. The oxidation process of PDMS must be well controlled. The right amount of oxidation can create enough hydroxyl and carboxyl functional groups on the surface for optimal bonding strength and surface wettability. However, excessive oxidation of the PDMS surface leads to the formation of a brittle layer of silica and results in decreased bonding strength.

Advantage of Tergeo plasma cleaner over competitors

  • Better plasma uniformity. PIE Scientific has carried out extensive research to improve the uniformity of the plasma generator. It’s extremely difficult to achieve a uniform rf electric field with an external inductor coil type antenna that is used by some cheap plasma cleaner. If a metal rf electrode is placed inside the plasma chamber, then it is intrinsically nonsymmetric in geometry. Plasma will be stronger close to the high voltage rf electrode, especially at the edge of the electrode. Tergeo plasma cleaner uses two symmetric external electrode designs to achieve much better plasma uniformity over other types of plasma cleaner designs.
  • Advanced process control technology. Plasma uniformity and strength can change with chamber pressure. Tergeo plasma cleaner uses advanced MEMS-based digital pressure sensor technology for pressure monitoring. In addition, PIE Scientific developed a unique plasma sensor technology that can quantitatively monitor the plasma strength in real-time. Quantitative data is the key to achieve repeatable and consistent results from day to day.
  • Fully automatic operation. In some basic plasma systems, the user needs to manually adjust the needle valve to introduce gas into the plasma chamber. It’s almost impossible to achieve a repeatable gas flow rate with manual coarse needle valves without any feedback. Tergeo plasma cleaner uses a fully automatic mass flow controller (MFC) to precisely regulate gas flow rate from 0 to 100sccm with accuracy better than 0.2 sccm. Fully automatic operation with multiple recipe support also ensures repeatable performance from day to day because the execution of the cleaning process is controlled by embedded microcomputers.