Micronit has developed a proprietary technique to integrate electrodes in glass chips, e.g. inside channels and reservoirs. Common used electrode materials include Pt, Au, Cu, and ITO (Indium Tin Oxide). Depending on the electrode material sputtering, evaporation or plating is used.
The electrodes inside fluidic channels are used for example for electrical impedance spectrometry, contact or contactless conductivity detection, amperometric detection, electrical heating and temperature sensing. Electrodes inside fluidic compartments are mainly used to apply high voltages to generate electroosmotic flow or to perform electrophoresis.
Electrodes can be integrated in between two glass or silicon layers or placed on top of the chip. Also thin insulating layers between electrodes and fluidic channels can be applied.
Field electrodes are used to conduct electrical current and generate electrical fields for controlling electroosmotic flows or to perform electrophoresis. Micronit Microfluidics has unique technology to integrate electrodes between glass layers.
Detection electrodes are used to measure the local electrical conductivity or impedance of the liquid in a fluidic channel. These electrodes are used for example for detection on capillary electrophoresis chips, but can also be used to count and characterize particles or biological cells.
Heating & sensing electrodes
The combination of electrical heaters and temperature sensors on a chip provides a convenient means to heat fluids inside microchannels and measure the temperature. This technology can also be used for creating a time-of-flight flowsensor.
Locally insulated electrodes
Electrodes embedded into a microfluidics chip can be used to make electrical contact with gas and fluids. Micronit has perfected a method to locally insulate these contact electrodes using a thin oxide layer on top of the electrodes. This insulation protects the electrodes, prevents electrolysis, and can be used to locally manipulate the zeta-potential of the channel wall.