Patterned adhesive enables construction of nonplanar three-dimensional paper microfluidic circuits

Abstract

This article discusses the fabrication of planar and nonplanar 3D paper microfluidic circuits through the use of patterned spray adhesive application and origami techniques. The individual paper layers are held together via semi-permanent adhesive bonds without the need for external clamps. Semi-permanent bonds accommodate the repeated folding and unfolding required by complex origami device structures and allow the device to be unfolded post-use to view internally displayed results. Combinations of adhesive patterns and fluid channel widths were identified that did not prevent the fluid from traveling between layers and through the entire circuit. Further, this method was extended to nonplanar 3D paper microfluidic circuits, demonstrated via multi-fluid wicking within a modified origami peacock. Such nonplanar 3D paper microfluidic circuits are expected to offer an entirely new platform for exploring new designs and functions of paper analytical devices.

Emerging Designs of Electronic Devices in Biomedicine

“…Microfluidic paper-based analytical devices (µPADs) represent a technology of hydrophilic/hydrophobic micro-channel networks and associated analytical devices for development of portable and low-cost diagnostic tools that improve point of care testing (POCT) and disease screening [86] involving the specific detection of biomolecules. They have the ability to perform laboratory operations on micro-scale, using miniaturized equipment, and can be fabricated by using 2-D [86][87][88] or 3-D [89,90] methods to transport fluids in both horizontal and vertical dimensions, depending on complexity of the diagnostic application. The principal techniques in the literature for fabrication of paper-based microfluidic devices include: wax printing [90], inkjet printing [91], photolithography [92], flexographic printing [93], plasma treatment [94], laser treatment [95], wet etching [96], screen printing [97], and wax screen printing [98].…”

Recent applications of paper‐based point‐of‐care devices for biomarker detection

“…extra fluidic channels) to the 2D‐PADs is not straightforward. Thus, 3D‐multilayers combining lateral and vertical flow components can be an interesting alternative to overcome these limitations and to further enhance the capability of PADs . Fabrication of 3D‐devices requires precise alignment of multiple layers, equipment, and materials to bond layers and modifications of the fabricated devices (e.g.…”

Origami Biosystems: 3D Assembly Methods for Biomedical Applications

“…Liu and Crooks have described a method to assemble 3D μPADs based on origami principles, where the stacking of 2D paper layers was achieved by sequences of hand‐folding of a single sheet of paper without the need of alignment methods . Other exciting origami biosystems have been reported following this assembly methodology where electrodes can be integrated and are activated by the folding process . Figure 4 a shows a photograph of an unfolded 3D μPAD device demonstrating the distribution of four colored solutions among nine paper panels that are folded into the 3D microfluidic μPAD.…”