An inkjet printed sensor for load measurement

Low cost direct printing technologies are assuming a terrific role for the development of sensors, with particular regards to bendable and flexible sensors addressing many applications. In this paper the development of a capacitive load sensor realized by low cost inkjet printing process is discussed along with its experimental characterization. The load sensor is based on a InterDigitated (IDT) capacitive Transducer, printed on a PET substrate, covered by a dielectric layer. The sensing methodology proposed as respect to traditional solutions based on resistive strain sensor is characterized by the absence of mechanics allowing the transduction between load and strain, which is usually implemented by cantilever architectures. Experimental results provide an estimated sensor resolution of 0.8 g.