Fast production of microfluidic devices by CO₂ laser engraving of wax‐coated glass slides

Abstract

Glass is one of the most convenient materials for the development of microfluidic devices. However, most fabrication protocols require long processing times and expensive facilities. As a convenient alternative, polymeric materials have been extensively used due their lower cost and versatility. Although CO2 laser ablation has been used for fast prototyping on polymeric materials, it cannot be applied to glass devices because the local heating causes thermal stress and results in extensive cracking. A few papers have shown the ablation of channels or thin holes (used as reservoirs) on glass but the process is still far away from yielding functional glass microfluidic devices. To address these shortcomings, this communication describes a simple method to engrave glass-based capillary electrophoresis devices using standard (1 mm-thick) microscope glass slides. The process uses a sacrificial layer of wax as heat sink and enables the development of both channels (with semicircular shape) and pass-through reservoirs. Although microscope images showed some small cracks around the channels (that became irrelevant after sealing the engraved glass layer to PDMS) the proposed strategy is a leap forward in the application of the technology to glass. In order to demonstrate the capabilities of the approach, the separation of dopamine, catechol and uric acid was accomplished in less than 100 s.

Recent trends in capillary electrophoresis for complex samples analysis: A review

“…Their fabrication increase the cost and takes longer time since the chips have to be individually designed and fabricated without the possibility of using a previous mold or template and require complex procedures and instrumentation. Alternatives to these fabrication methods have been proposed, as the application of CO 2 laser (a procedure usually applied to polymeric materials) to the engraving of the reservoir and microchannels system on glass device that requires the application of an initial paraffin wax layer onto the glass surface in order to dissipates the generated heat during the engraving process . However, the connection to other systems can be difficult in some cases due to their rigid nature, and their nonpermeability to gases prevents their application to cell studies .…”

Potential of a sensitive uric acid biosensor fabricated using hydroxyapatite nanowire/reduced graphene oxide/gold nanoparticle

“…The conventional test methods for UA concentration include chemical methods, spectrophotometry, enzymatic-colorimetric method (Hall, 2008), electroanalysis (Sun, Lee, Yang, & Wu, 2011), chromatography (Ensafi & Karimi-Maleh, 2010), and fluorimetry (Arora, Nandwani, Bhambi, & Pundir, 2009). Some shortcomings of these methods, such as expensive, complex, and unbefitting for real clinical analysis (Da Costa et al, 2016), are undeniable. By contrast, electrochemical biosensor is an attractive alternative due to its simplicity, low cost, excellent selectivity, and high sensitivity (Wang, Gao, Sun, & Xu, 2014;Xu, Liu, Su, Liu, & Qiu, 2011;Zhao, Yu, Tian, & Xu, 2016).…”

Performance Evaluation of Free-Space Fibre Optic Detection in a Lab-on-Chip for Microorganism

“…Various methodologies of LOC fabrication have been widely adopted involving materials such as paper [13], glass [14,15], polymers [16,17], and ceramic [18,19]. The material chosen depends on the application, physicochemical properties of the analyte, biocompatibility, and possibly integration with other devices and materials [16].…”