Low temperature bonding of PMMA and COC microfluidic substrates using UV/ozone surface treatment

Abstract

The use of UV/ozone surface treatments for achieving low temperature bonds between PMMA and COC microfluidic substrates is evaluated. Low temperature bond strengths, approaching those of native polymer substrates bonded above their glass transition temperatures, are demonstrated for both thermoplastics. To evaluate the effects of the UV/O(3) surface treatment on the operation of bonded microfluidic devices, the relationship between UV/O(3) exposure and polymer hydrophilicity and surface chemistry are measured. Post-treatment surface chemistry is evaluated by XPS (X-ray photoelectron spectroscopy) analysis, and the stability of the treated surfaces following solvent exposure is reported. Electroosmotic flow within fabricated microchannels with modified wall surfaces is also characterized. Overall, UV/O(3) treatment is found to enable strong low temperature bonds between thermoplastic microfluidic substrates using a simple, low cost, and high throughput fabrication technology.

Poli(metilmetakrilatoa)ren gainazal eraldakea. Sentsore adimendunak

“…Bestalde, ozonolisiaren kasuan, horretarako bereziki eraiki den makina batean, ozono tratamendua denbora ezberdinetan jasan dira, 10 minututik 50 minutura [12]. Horretarako, laginak lanpara ultramore batean jarri dira, Hammatsu L8868, 200 W-eko potentziaz, Hg-Xe lanparari esker.…”

A Semi-Closed Device for Chromosome Spreading for Cytogenetic Analysis

“…Plasma surface treatment tunes the surface properties to promote adhesion, diminish the surface roughness and enhance wettability [20]. However, active radicals on plasma treated surface reduce the treatment stability and hydrophobicity recovers to the initial value during two weeks observation period in case of argon and oxygenated-argon plasma [21,22]. In the present investigation several of the Topas slides were only treated with oxygen plasma to compare the recovery rates and long term stability with the proposed combined technique.…”

Miscible Organic Solvents Soak Bonding Method Use in a PMMA Multilayer Microfluidic Device

“…However, the microstructures can be damaged by thermal or pressure easily, since the temperature is kept around glass transition temperature (Tglass). Two methods are often used to solve this problem: reduce the bonding pressure or temperature by using surface modification technology [14][15][16][17][18] or add embedded filler layer to protection micro structures [19][20][21]. However, even without considering the complex modification process, the thermal and pressure cannot be effectively transmitted to the middle layer, in that case leakage occurs; while removing the filler layer of multilayer devices in second method is not easy either.…”