Packaging of microfluidic chips via interstitial bonding technique

Abstract

In this paper, we describe an interstitial bonding technique for packaging of microfluidic chips. The cover plate is first placed on top of the microfluidic chip, followed by dispensing the UV-curable resin into the resin-loading reservoirs. With the interstitial space between the cover plate and the microfluidic chip connecting to the loading reservoirs, the UV-curable resin wicks through capillary force action and hydrostatic pressure generated by the liquid level in the resin-loading reservoirs. When reaching the microchannels, the UV-curable resin stops flowing into the microchannels due to the force balance between the surface tension and hydrostatic pressure. The assembly is then placed under the UV light, followed by further curing in the thermal oven. It is found that there is no leakage from the bonded microfluidic chips and a good DNA separation result was obtained by using the microfluidic chips as fabricated. This bonding technique is relatively simple and fast, which can be applied to the packaging of microfluidic chips made from hybrid materials with complicated designs as long as the interstitial space connects to the loading reservoirs.

Modular Architecture of a Non-Contact Pinch Actuation Micropump

“…Finally, the PMMA substrate was removed from the oven and de-molded immediately to avoid device cracking due to internal stress (Figure 5(c)). Figure 5(d,e) shows the adhesion of the PMMA cover lid (with predrilled chamber and inlet and outlet reservoirs) to the diffuser layer via the UV interstitial technique under room temperature [23]. Further elaboration of the bonding procedure is discussed in the literature [24].…”

Adhesive bonding of microfluidic chips: influence of process parameters

“…For adhesive bonding, reactive adhesives (two-component, e.g. epoxy) [6,9,10] and UV-curable adhesives [8,[11][12][13] are most frequently applied. However, the UV light in the bonding process of the latter can possibly denature stored bioreagents if not masking the respective areas and preventing reflection or scattering.…”

“…Multiple approaches for bonding of microfluidic chips like laser welding [6], thermal bonding [7] or adhesive bonding [6,[8][9][10][11][12][13] currently exist. Depending on the boundary conditions for lab-on-a-chip development, e.g.…”

“…Further, no bioreagents can be immobilized on the lid. Thus, different approaches to only selectively cover the chip surface with adhesive have been reported, namely contact printing [6,9,10,13], the use of guide channels [8,12] or by a laminator [11]. The so far presented work allows for selecting a general approach for bonding.…”

Photolamination bonding for PMMA microfluidic chips

“…Many bonding techniques for producing plastics microfluidic chips had been demonstrated including thermal bonding, adhesive or UV-curable resin bonding, solvent bonding, plasma/UVO aided bonding, microwave or ultrasonic welding (Martynova et al 1997;Liu et al 2001;Lai et al 2004;Lu et al 2008;Shah et al 2006;Lin et al 2007;Mair et al 2007;Wallow et al 2006;Sun et al 2007;Yussuf et al 2005). However, problems related to channel deformation, contamination of solvent residue, tedious procedures have limited the applications of these technologies.…”