Development of inkjet printed strain sensors

Strain sensors with different architectures such as single sensors, sensor array and matrix have been developed by inkjet printing technology. Sensors with gauge factors up to 2.48, dimensions of 1.5 mm x 1.8 mm with interdigitated structures with a distance of 30 µm between the finger lines have been achieved based on PeDOT (poly(3,4-ethylenedioxythiophene) and conductive ink. Strain gauges based on silver ink have been also achieved with a gauge factor of 0.35. Performance tests including 1000 mechanical cycles have been successfully carried out for the development of smart prosthesis applications.This work is funded by FEDER funds through the "Programa Operacional Factores de Competitividade – COMPETE" and by national funds arranged by FCT- Fundação para a Ciência e a Tecnologia, project references NANO/NMed-SD/0156/2007, PTDC/CTM/73030/2006 and PTDC/CTM/69316/2006. The authors also thank support from the COST Action MP1003, 2010 ‘European Scientific Network for Artificial Muscles’. VC thank the FCT for the SFRH/BD/48708/2008 grants, respectively. The authors also thank funding from Matepro –Optimizing Materials and Processes”, ref. NORTE-07-0124-FEDER-000037”, co-funded by the “Programa Operacional Regional do Norte” (ON.2 – O Novo Norte), under the “Quadro de Referência Estratégico Nacional” (QREN), through the “Fundo Europeu de Desenvolvimento Regional” (FEDER). We would also like to thank the Civil Department of Universidade do Minho in particular to Carlos Palha for their support in performing the experimental tests