Microfluidics fuel cell – Prof Suddhasatwa Basu (PI)

A microfluidic fuel cell is an electrochemical device that produces electrical power through electrochemical reactions involving a fuel and an oxidant. Microfluidic fuel cell systems exploit co-laminar flow to separate the fuel and oxidant species, in contrast to conventional fuel cells employing an ion exchange membrane for this function. In NRF, microfluidic fuel cell (MFC) is fabricated using Y-shape polydimethylsiloxane (PDMS) microchannel of dimension 800 μm × 125 μm × 37 mm aligned and soft bonded to metallized glass slides, which acted as anode and cathode with an active area of 0.11 cm2.The carbon nitride (CNx), a nitrogen-containing carbon material nano fiber is used as cathode catalyst in MFC to avoid the use of noble metal. Formic acid is used as fuel and KMnO4 as oxidant. For the cathode, firstly Ti layer (10 nm) was deposited as the adhesion layer, followed by Au layer (50 nm), as the current collector layer. CNx nanofibers cathode catalyst was synthesized using electrospinning. Similarly for the anode, firstly Ti layer (10 nm) was deposited as the adhesion layer, followed by Pt layer (50 nm) as the anode and current collector layer. When operated at 300 mL min-1 flow rate, MFC gives maximum power density of 3.43 mW cm-2 and current density of 9.79 mA cm-2.

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Fig 1: Assembled microfluidic fuel cell

The group is currently working on the development of microfluidic cell for water electrolysis to generate H2 and O2 and this will be operated in conjunction with MFC to generate decent power density.

 

Capillary electrophoresis amperometric detector microchip for sensing applications Dr Sandeep Kumar Jha (PI) and Prof Suddhasatwa Basu (Co-PI)

In this project, we are working on the development of a capillary electrophoresis amperometric detector microchip mainly for two analytical applications: separation and simultaneous detection of potential neurotransmitters e.g., dopamine, epinephrine and serotonin present in human body; separation and in-channel amperometric detection of major flavonoids and phenolic acids present in fermentation products (beer/wine sample). The developed microchip has a potential to be used as a point-of-care testing device to observe the neurotransmitters level during normal/emergency medical conditions. Beside this, the fabricated microchip can be integrated with fermentation reactor for continuous monitoring of the products in an automation mode. In NRF, the microchip is being developed by using standard photolithography process. The polydimethoxysiloxane (PDMS) engraved microchannel of the developed microchip has been prepared through photolithography and negative moulding method. The dimension of the microchannel has been fixed to 100-125 µm during preparation. The microelectrodes on glass substrate have been fabricated via photolithography and metal deposition method. For that purpose, first the microelectrodes pattern has been made by photolithography and then titanium as adhesion layer and gold as electrode material have been deposited on the patterned glass substrate by e-beam evaporation system. Finally, the PDMS mold with engraved microchannel, and the glass substrate with gold microelectrodes, have been aligned and bonded by using oxygen plasma/UV-ozone treatment. The image of the developed microchip device with microchannel and microelectrodes is shown in Figure 2.

Figure 2: Fabricated microchip after alignment and bonding

Figure 2: Fabricated microchip after alignment and bonding