Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices

Abstract

We demonstrate the use of patterned aerosol adhesives to construct both planar and nonplanar 3D paper microfluidic devices. By spraying an aerosol adhesive through a metal stencil, the overall amount of adhesive used in assembling paper microfluidic devices can be significantly reduced. We show on a simple 4-layer planar paper microfluidic device that the optimal adhesive application technique and device construction style depends heavily on desired performance characteristics. By moderately increasing the overall area of a device, it is possible to dramatically decrease the wicking time and increase device success rates while also reducing the amount of adhesive required to keep the device together. Such adhesive application also causes the adhesive to form semi-permanent bonds instead of permanent bonds between paper layers, enabling single-use devices to be non-destructively disassembled after use. Nonplanar 3D origami devices also benefit from the semi-permanent bonds during folding, as it reduces the likelihood that unrelated faces may accidently stick together. Like planar devices, nonplanar structures see reduced wicking times with patterned adhesive application vs uniformly applied adhesive.

Fabrication of Three-dimensional Paper-based Microfluidic Devices for Immunoassays

“…22 We use a sequential, layer-by-layer approach to manufacture three-dimensional paper-based microfluidic devices. In contrast to those methods that apply folding or origami techniques to produce multilayer devices from a single sheet of paper 23,24 additive manufacturing offers a number of advantages: (i) Multiple materials can be incorporated into a single device architecture without modification to methods for the printing, alignment, or assembly of layers. (ii) Patterned adhesive films can be integrated into the assembly process.…”

Dewetting and photochemical crosslinking of adhesive pads onto lithographically patterned surfaces

“…For structural reasons, homogeneous adhesive layers are unfavorable due to failure by film instabilities or by crack propagation . For functional reasons, discontinuous or discrete adhesive layers are often desired: for example, (1) when multiple small parts should be assembled onto the same substrate in microsystems packaging, or (2) when the adhesive interface should remain permeable for liquid transport in microfluidic devices …”