Design of an organic electronic label on a flexible substrate for temperature sensing

We demonstrate an organic smart label electronic system using p-type organic thin film transistors (OTFT) for temperature sensing applications. The electronic label consists of all organic temperature sensor, memory, logic and interface circuits and detects whether the critical temperature threshold value has been exceeded and records the data digitally in write-once-read-many (WORM) form that can be transmitted to a reader through wireless communication. A comparator is used to interface the sensor to the logic part. The logic circuit block processes and bundles the sensor information along with the necessary additional information that is required for a successful wireless transmission. We have demonstrated the operation of the reported organic smart label system using a silicon based modulator/rectifier circuit for RF communication. The organic logic circuit was built using standard cell design approach with approximately 180 p-type OTFTs. All the circuits were operated with a V_DD of -20 V.