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Indexed by:期刊论文

Date of Publication:2015-03-01

Journal:MICROFLUIDICS AND NANOFLUIDICS

Included Journals:SCIE、EI、Scopus

Volume:18

Issue:3

Page Number:527-535

ISSN No.:1613-4982

Key Words:2D nanofluidic devices; Nanochannels; Surface modification; Thermal bonding

Abstract:An oxygen plasma-assisted thermal bonding technique is demonstrated for sealing a two-dimensional (2D) polymer-based nanofluidic device. A polymethyl methacrylate (PMMA) substrate with 2D nanochannels and polyethylene terephthalate (PET) cover plate with microchannels was treated with optimized oxygen plasma parameters: chamber pressure of 1 mbar, power of 30 W and time of 2 min. The effective bonding area and bonding strength were significantly improved under the optimized bonding temperature of 70 A degrees C, pressure of 0.5 MPa and time of 10 min. Nanoindentation experiments showed that oxygen plasma treatment did not change the PET or the PMMA modulus, which provides a novel sampling method to observe the profile structures of the deformation of 2D nanochannels by scanning electron microscope. The 2D PMMA-PET nanofluidic device with 89 (+/- 2) nm wide and 84 (+/- 2) nm deep nanochannels was successfully bonded under optimized process parameters. The total dimension loss of the 2D nanochannels was estimated to be 2 (+/- 4) nm in width and 12 (+/- 4) nm in depth. The deformation loss in depth is mainly attributed to sagging of the PET cover plate (10 nm) during the thermal bonding process. Experiments with Rhodamine B solution showed good sealing properties of the polymer-based 2D nanofluidic device without leakages and clogging. This bonding process provides a high potential technique for fabrication of 2D polymer-based nanofluidic device with low deformation loss, low cost and high throughput.