Active matrix-based pressure sensor system with a 4 × 16 printed decoder designed with a flexible hybrid organic process design kit

Abstract

The innovative field of printed sensor with a demand for high accuracy, sensitivity and durability has enabled a wide application area in sensing, healthcare etc. A large-area printed sensor system on a flexible foil substrate emplying p-type organic field-effect transistors (OFETs) is presented. Thereby, the OFET is fabricated through a hybrid manufacturing process, including photolithographically structured source- and drain-electrodes, ink-jet printed organic semiconductor, and spin-coated dielectric. Moreover, a dedicated device model, derived from the Variable Range Hopping (VRH) model, is developed and integrated together with process related design rules, materials properties and geometric information into a comprehensive process design kit (FH_OPDK). The FH_OPDK is integrated in a commercial Electronic Design Automation (EDA) tool and is used to design and perform post-layout simulations on logic gates, such as INV, NAND2, and NOR2 as well as circuitry such as ring oscillators and a 4x16 digital decoder. Several circuit topoplogies have been tested and evaluated in a detailed Model-Hardware Corelation analysis. Finally we have optimized logic gates and the decoder in a PMOS only, pseudo CMOS design style. To demonstrate the feasibility of the full sensor system in hardware a 16x16 active matrix pressure sensor on a flexible stubstrate (PET) integrated with a 4x16 binary decoder was fabricated and tested. We have integrated our flexible hybrid sensor system with a PCB board and a microcontroller to demonstrate the hardware readout platform capable of detecting the weight of objects and visualizing a digital map of applied forces.