Interdigital Transducer (IDT)

Interdigital transducers (IDT) are the core components of electrochemical sensors. At Fraunhofer EMFT, these components are available for impedimetric, amperometric or potentiometrich measurements.

The methods of microelectronics and microsystem technology are optimal for producing compact, high-performance transducers. For this, the researches at Fraunhofer EMFT deploy precious metals like gold or platinum, but also organic conductors and nanomaterials. These are applied on silicon, glas, ceramics or flexible substrates using thin film or printing technologies, according to the individual needs of the customers.

Interdigital Transducer for Impedimetric Measurements

The interdigital transducers for impedimetric measurements consist of interdigital electrode configurations (comb structures) and are suited for capacitive and conductive measurements.

Interdigital-Transducer Chip
© Fraunhofer EMFT
Interdigital-Transducer Chip


Comb structure design Polygon
Chip surface area 4,5 x 4,5 mm
Material Gold electrodes on glass or foil 
Finger distance  ≥ 3µm
Center electrode yes
Passivation Polyimid at need
Capacity > 8 pF
Amperometric measurements yes
Integrated temperature sensor Resistance (RT upto 200 °C)
Integrated heater upto 200 °C
Coating at customer request
Packaging Wire bond, PCB with ZIF connector

Multi-Electrode Transducer for Amperometric and Impedimetric Measurements

In this type of transducer, the electrode of an electrochemical cell is implemented as an interdigital structure (IDT).

Multi-electrode transducer on a flexible PCB
© Fraunhofer EMFT / Bernd Müller
Multi-electrode transducer on a flexible PCB

Electrode design circular
Diameter of the working electrode (WE) 2000 µm
Chip surface area 18 x 6,75 mm
Material Gold electrodes on glass 
Reference electrode (RE) Possibility to print Ag/AgCl
Finger distance (IDT) ≥ 5µm
Passivation At need; polyimide (photo structured)
Coating At customer request

These semiconductor components are available at Fraunhofer EMFT for your application topics. We look forward to hearing from you!

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