Comparison of Ultrasonic Welding and Thermal Bonding for the Integration of Thin Film Metal Electrodes in Injection Molded Polymeric Lab-on-Chip Systems for Electrochemistry

Abstract

We compare ultrasonic welding (UW) and thermal bonding (TB) for the integration of embedded thin-film gold electrodes for electrochemical applications in injection molded (IM) microfluidic chips. The UW bonded chips showed a significantly superior electrochemical performance compared to the ones obtained using TB. Parameters such as metal thickness of electrodes, depth of electrode embedding, delivered power, and height of energy directors (for UW), as well as pressure and temperature (for TB), were systematically studied to evaluate the two bonding methods and requirements for optimal electrochemical performance. The presented technology is intended for easy and effective integration of polymeric Lab-on-Chip systems to encourage their use in research, commercialization and education.

Lab-on-a-disc platform for screening of genetically modified E. coli cells via cell-free electrochemical detection of p-Coumaric acid

“…Although the observed E p was greater than 59 mV, which is the theoretically expected value for a reversible single-electron transfer reaction such that of ferri/ferrocyanide (A.J. Bard, 2001), the values are comparable with those reported for gold electrodes fabricated on glass (Andreasen et al, 2015), plastic (Matteucci et al, 2016) and silicon substrates (Zor et al, 2014). CVs for 8 electrodes on the same disc acquired in 10 mM ferri/ferrocyanide using PBS (pH 7.4) as supporting electrolyte (scan rate 50mVs −1 ).…”

“…Metal electrodes are most commonly fabricated on silicon or glass substrates although there are reports describing electrode fabrication on plastic substrates aiming at creating low-cost (Xu et al, 2011) and easy to integrate electrodes for microfluidic applications (Matteucci et al, 2016;Šnita et al, 2009). Patterning electrodes on plastic substrates can be achieved in a cost-efficient way by screen printing (Metters et al, 2011) or by using a stencil or shadow mask in combination with e-beam evaporation (Amato et al, 2015;Xu et al, 2011).…”

Recent Advancements towards Full-System Microfluidics

“…To date, research is actively underway to develop methods which are both effective and compatible with current production standards. In the recent paper from the Matteucci group, a rigorous comparison of sealing via ultrasonic welding and thermal bonding [ 28 ]. The authors compared electrochemical performance following the bonding of injection moulded microfluidic chips with embedded thin-film gold electrodes.…”

Rapid prototyping of PET microfluidic chips by laser ablation and water‐soaking bonding method

“…However, upheaval area was usually generates along the microchannel, since high temperature of laser beam makes the material near the edge of the microchannel deformed upwardly [13]. In this case, to fully bond the microchannels, traditional thermal bonding encounters high microchannel deformation and serious blocking issues due to the adoption of high temperature and pressure [14]. Interlayer bonding method can fully bond the microchannels without the damage of microchannels [15].…”