Rapid prototyping of microfluidic devices with integrated wrinkled gold micro-/nano textured electrodes for electrochemical analysis

Abstract

Fully-integrated electro-fluidic systems with micro-/nano-scale features have a wide range of applications in lab-on-a-chip systems used for biosensing, biological sample processing, and environmental monitoring. Rapid prototyping of application-specific electro-fluidic systems is envisioned to facilitate the testing, validation, and market translation of several lab-on-a-chip systems. Towards this goal, we developed a rapid prototyping process for creating wrinkled micro-/nano-textured electrodes on shrink memory polymers, fabricating microfluidics using molds patterned by a craft-cutter, and bonding electrical and fluidic circuitries using a PDMS partial curing method optimized for creating void-free bonds at the side walls and surfaces of tall (>5 μm) micro-/nano-textured wrinkled electrodes. The resulting electro-fluidic devices, featuring closely spaced high topography electrodes for electrochemical analysis, can withstand flow-rates and burst pressures larger than 25 mL min(-1) and 125 kPa, respectively. In addition, the fully-integrated electrochemical flow-cell developed here demonstrates excellent electrochemical behaviour, with negligible scan to scan variation for over 100 cyclic voltammetry scans, and expected redox signatures measured under various voltage scan rates and fluidic flow rates.

Hierarchical Structures, with Submillimeter Patterns, Micrometer Wrinkles, and Nanoscale Decorations, Suppress Biofouling and Enable Rapid Droplet Digitization

“…The PDMS channels were then bonded to the PS‐Planar or PS‐AuNP‐Shrunk through wet bonding. [ 63 ] This was done by creating a thin layer of PDMS (10:1) by depositing 400 µL PDMS in a petri dish and spin coating for 30 s at 7000 rpm. The PDMS channel was stamped on the spin coated layer then placed carefully on PS‐Planar or PS‐AuNP‐Shrunk and cured overnight.…”

Thermally robust and biomolecule-friendly room-temperature bonding for the fabrication of elastomer–plastic hybrid microdevices

“…Furthermore, it was higher than those realized by other previously reported methods performed at room temperature 3,12 and, in our case, was attained via much simpler and faster procedures. For this reason, the method introduced in this study can be considered a promising option for certain types of devices requiring relatively low-pressure (∼ 35 kPa) 22 experimental conditions, such as for cell patterning, or when electrodes are integrated in microdevices that must withstand pressures from 125 to 300 kPa 23,24 . Fig.…”

Superwetting and aptamer functionalized shrink-induced high surface area electrochemical sensors

“…Research in the use of "high surface area" electrodes presents a clever solution to this problem in which one creates a rough micro-and/or nanostructured surface topography that considerably enhances the working electrode's electrochemically active surface area (EASA) relative to its macroscopic footprint. While complex chemical deposition methods to this end have been available for decades (Salvarezza et al, 1990;Gabardo et al, 2015;Sonney et al, 2015), recent research has shown that enhanced EASA can be achieved more simply by heat-shrinking a polymer substrate coated with metal thin film electrodes (Gabardo et al, 2013;Pegan et al, 2013). Fabrication of these shrink electrodes is low-cost and does not require sophisticated equipment or clean-room facilities.…”