Bonding PMMA microfluidics using commercial microwave ovens

Abstract

In this paper, a novel low-cost, rapid substrate-bonding technique is successfully applied to polymethyl methacrylate (PMMA) microfluidics bonding for the first time. This technique uses a thin intermediate metallic microwave susceptor layer at the interface of the bonding site (microchannels) which produces localized heating required for bonding during microwave irradiation. The metallic susceptor pattern is designed using a multiphysics simulation model developed in ANSYS Multiphysics software (high-frequency structural simulation (HFSS) coupled with ANSYS-Thermal). In our experiments, the required microwave energy for bonding is delivered using a relatively inexpensive, widely accessible commercial microwave oven. Using this technique, simple PMMA microfluidics prototypes are successfully bonded and sealed in less than 35 seconds with a minimum measured bond strength of 1.375 MPa.

Safe and cost-effective rapid-prototyping of multilayer PMMA microfluidic devices

“…The only method which can be performed more quickly (Toossi et al 2015) requires the deposition of a gold layer to allow microwave heating at the surfaces. The present technique is the fastest and presents deformation in the lowest range and is the only technique that has been demonstrated with up to 19 PMMA layers.…”

“…Furthermore, both methods can lead to clogging of the channels (Lin et al 2007). Variants of the aforementioned solutions include the use of UV light to activate surfaces (Tran et al 2013), microwave heating combined with a conductive layer [patterned gold (Toossi et al 2015), conductive polymer (Holmes et al 2011) or metal clips acting on a solvent layer (Mona et al 2010)], or plasma treatment , which can be optimised to reach a bonding strength of 0.57 MPa in 20 min (Zhifu et al 2015). Generally these procedures are time-consuming and require specialist equipment (Lin et al 2007).…”

Characterization and Integration of Terahertz Technology within Microfluidic Platforms

“…Such polymers can be patterned into microfluidic platforms at relatively low cost and can offer varying levels of chemical resistance and biocompatibility. Some, such as PMMA, offer strong chemical resistance [ 21 , 22 , 23 ], while others, such as PDMS, offer excellent biocompatibility [ 19 ]. Unfortunately, less is known about the THz absorption characteristics of the polymers and their impact in microfluidics-based THz-TDS systems.…”

Polymer Microfluidics: Simple, Low-Cost Fabrication Process Bridging Academic Lab Research to Commercialized Production

“…Indirect bonding is defined as bonding that involves the use of an additional material or chemical reagents to assist in the bonding, such as epoxy, adhesive tape, or chemical reagents. Indirect thermoplastic bonding methods, such as adhesive bonding [ 49 , 50 , 51 ] or microwave bonding [ 52 ], use an intermediate layer, such as metal or a chemical reagent.…”