Fabrication of planar nanofluidic channels in thermoplastic polymers by O ₂ plasma etching

Fabrication of PMMA nanofluidic electrochemical chips with integrated microelectrodes

“…The etching process was performed by using a commonly used plasma cleaner instead of some special and expensive tools, such as inductively coupled plasma (ICP) or reactive ion etching (RIE) systems, which makes it accessible by most academic institutions. The process parameters of the plasma cleaner were optimized based on previously published procedures (Liu et al, 2012). Under the optimized condition with RF power of 60 W and chamber pressure of 200 Pa, the dependence of the etching depth of a planar nanochannel with a width of 2 μm on etching time was studied.…”

“…The T g of PMMA is 105°C. We once developed a plasma-assisted thermal bonding method to realize a low-temperature (85°C) bonding of PMMA nanofluidic chips (Liu et al, , 2012. However, under the same bonding condition, it was observed that sub-microchannels on the nanofluidic biosensor collapsed.…”

“…The bonding temperature was optimized when the bonding pressure and time were kept constant. The optimized temperature was 70°C, which is 15°C lower than that used in the plasma-assisted thermal bonding method (Liu et al, 2012). Five nanofluidic biosensors were consecutively bonded at 70°C, and three out of five chips presented both complete bonding and unblocked channels.…”

“…Plasma etching is compatible with photolithography techniques, and has been proved to be a good method for fabricating polymer microstructures, such as waveguides (Inoue et al, 2003), microchannels (Rossier et al, 2002), and even nanochannels (Liu et al, 2012). In this study, a novel method based on plasma etching was proposed for monolithically integrating planar nanochannels and microelectrodes on a single poly (methyl methacrylate) (PMMA) plate, and complete PMMA nanofluidic electrochemical chips with integrated microelectrodes were for the first time constructed by bonding with another PMMA plate containing microchannels.…”

Rapid, Single-Molecule Assays in Nano/Micro-Fluidic Chips with Arrays of Closely Spaced Parallel Channels Fabricated by Femtosecond Laser Machining

“…Another inventive method involves forming nanochannels on a Petri dish lid and casting them in a polymer film [ 11 ]. A different approach uses photolithography and oxygen plasma to etch channels with submicron depths in thermoplastic polymers [ 12 ]. However, the development of a highly parallel fluidic platform, whether microscale or nanoscale, that integrates the ability to probe all channels simultaneously with single-molecule sensitivity remains an active research field.…”