Senaka Krishna Kanakamedala

Polymer based transistors & microfluidic devices for biosensor applications

Advisor : Dr. Mark A DeCoster

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Louisiana Tech University, Ruston, LA, USA

OECT : Low operating voltages , Aqueous environments & Simplified structure Electrode materials : Gold, silver and platinum Channel: Conducting polymersElectrolyte solution for electrochemical reactions

Introduction : Organic Electro Chemical Transistors (OECT)

Source (S)Drain (D)

Gate (G)

Electrolyte

Polymer channel2

OECT with Optimized Dimensions

3Fig: Schematic diagram of the OECT (top view)

Electrode & Channel material: PEDOT:PSS (conducting polymer)

OECT on Glass (left) & Polyester sheet (right)

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Fabricated Transistors

Film Thickness = 200 nm

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Surface roughness of the patterned film

Fig: AFM image of the PEDOT:PSS film

Transistors Characteristics

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Vds = Drain voltage, Ids = Drain current, and Vgs = Gate voltage

Glucose Sensor Response

I0 = Drain current before adding glucose

IC = Drain current after adding glucose (concentration of interest)

―

Normalized Response

I0 - IC

I0 =

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Micromolar Glutamate Sensing

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Glutamate Release from Tumor Cells

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Developed Field Effect Transistors

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4.5 mm

4.6 mm

Two sensor devices on a single chip

Gold electrodes are separated by a narrow channel

Channel length = 50µm

Flexible disposable micromixer

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Inlet 1Inlet 2

Outlet

Fig : Solid works model of the polymer micromixer (left), three layered polymer patterns constitute microchannel of the micromixer (right)

Fabricated flexible microfluidic devices

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