Conference Paper

Fully printable, flexible, large area organic optothermal sensors for human-machine-interfaces

DOI: 10.1109/ICSENS.2009.5398503 Conference: Sensors, 2009 IEEE
Source: IEEE Xplore

ABSTRACT Pyroelectric sensors presented in this work are based on polymers from the PVDF family which are comprised of a piezo- and/or pyroelectric polymer thin film capacitor, integrated with high performance organic thin film transistors operating at low voltages and acting as impedance converters, signal amplifiers and conditioners. For flexible integration with diverse electronic devices, large area processes applicable for industrial partners such as screen printing have been used for the fabrication of the sensors. With respect to the intended purpose for detection of human body radiation the absorbance of the impinging IR-light is dramatically increased by the application of printed carbon top electrodes, hence meeting the requirements for low-cost large area processability. Here we present good working integrated sensor devices based on two components, being an organic thin film transistor with a high-k-nanocomposite gate dielectric and a PVDF- copolymer based sensor. Besides, the integration of printed electrochemical transistors with printed sensors for large area applications has been realized successfully.

0 Bookmarks
 · 
78 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this work we present a flexible pyroelectric sensor composed by a PVDF-TrFE capacitor realized on ultra-thin polyimide film (5 �m thick), integrated with a n-channel low temperature polysilicon thin film transistor also fabricated on ultra-thin polyimide (8 �m thick). Exploiting a multi-foil approach, the pyroelectric capacitors and the transistors were attached one over the other reaching a final thickness of about 15 �m. The bottom contact of the sensor capacitance was connected to the gate of the transistor by a silver ink, while, for bias and load resistances, we used external elements. The active sensor area was defined by a circular capacitor with a diameter of about 2 mm. In order to enhance PVDF-TrFE pyroelectric properties, an external stepwise voltage was applied to the structure up to values of 160 V at a temperature of about 80 ◦C. The devices were then tested, at different working frequencies (up to 800 Hz) under a specific infrared radiation provided by a He–Ne laser, with a wavelength of 632 nm and maximum power of 5 mW. An output signal of tens of millivolt was observed at 10 Hz, exploiting the pre-amplification of polysilicon thin film transistor.
    Sensors and Actuators A Physical 07/2012; · 1.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Functional materials such as piezoelectric and pyroelectric polymers or organic photodiodes are promising candidates for flexible sensor surfaces; combining thin films of these materials with large-area resistive electrodes leads to position-sensitivity for passive touch- or light-point localization, respectively. However, this type of large-area sensors for passive stimulus-localization lacks a general theoretical description, which is necessary to understand the physics underlying the sensor concept.To this end we present a one-dimensional, theoretical model for these sensors; the model is based on the solutions of the telegrapher’s equations under the appropriate boundary conditions. We specify the applied boundary conditions, list approximate solutions for certain parameter ranges and present two model-based normalization procedures. These normalization procedures allow for stimulus localization independently of its magnitude and significantly increase the quality of the measurement signals. Experimental results agree well with theoretical findings, proving the suitability of the presented theoretical models.
    Sensors and Actuators A Physical 02/2013; 202:37-43. · 1.84 Impact Factor

Full-text

Download
22 Downloads
Available from
May 26, 2014