Dispositivos eletrônicos e eletroquímicos flexíveis, dobráveis e vestíveis à base de papel

In this work we have developed a new patterning method of carbon nanostructures on paper to fabricate high performance flexible, foldable, and wearable electronic/electrochemical devices. It is extremelly challenging to fabricate carbon-based nanostructures on paper that has the potential to meet some of the recent demands of paper-based devices, namely: (i) low sheet resistance, (ii) high folding stability, (iii) flexible electrochemical cells with high performance and (iv) tunable electric properties to fabricate motion and wearable sensors. The method that I will demonstrate is based on the use of sacrificial adhesive layers, SAL method. With this method it is possible to print different compositions of binder/carbon black with no extra care related to viscosity, particle size and solvent composition. Figure 1(a) shows a photo of the flexible carbon black (CB) tracks on paper. The carbon black tracks has low sheet resistance (250 Ω sq- 1) and a high-record folding stability (20,000 cycles). I will also demonstrate the fabrication of a 3D paper-based electrochemical cell made from a single carbon-black track (Figure 1(b). Moreover, the ink was tailored in order to electrochemically detect biologically relevant molecules at low potentials. CB circuits can be fully smashed and operated again with no significant response loss (Figure 1(c)). Finally, we have created bioinspired motion and wearable devices (Figure 1d) by locally tuning the electrical properties of the CB tracks. The fundamentals and the applications of this method will be presented in detail.