No abstract

No abstract

This paper presents a humidity sorption sensor made with an ink-jet printing technique. Nafion was applied as a humidity sorption material. After the presentation of sensor construction and sensor fabrication technology, a lot of effort has been made for detailed sensor tests and characterization. The sensor model based on a RC transmission line with distributed parameters (Jachowicz and Senturia 1981/1982 Sensors Actuators 2 171–86) has been carefully described and validated by a comparison with the sensor empirical parameters, measured in a broad range of measurement frequencies. On the basis of achieved results, some general conclusions for humidity sorption sensors on both the sensor fabrication technology and the sensor modelling have been made and presented in this paper.

Wireless sensors are fabricated on flexible plastic films by means of screen printing and via-hole filling. The wireless sensors are battery free with data and power transmission functions. The sensors, fabricated on polyethylene terephtalate films, are designed based on RFID technology. Using an additive patterning process known as screen printing, metallization on polymer films is created. Both sides of a polymer film are printed with metallic patterns and connected with micro vias filled with conductive paste. One side of the film consists of printed electrical traces for discrete components like resistors and transistors that would be mounted onto it; the other side consists of a printed inductive coil used for wireless data and power transmission. The micro vias, which have a diameter of 120 lm, are formed by mechanical punching and filled with conductive silver paste. The size of one sensor unit is approximately 2 cm 9 1.5 cm; an array of 4 9 7 sensor units are printed over an area of 15 cm 9 15 cm on a PET film. Details of manufacturing processes, component assembly and functionality test are presented in this paper.

No abstract