An all-inkjet printed flexible capacitor on a textile using a new poly(4-vinylphenol) dielectric ink for wearable applications

This paper reports a flexible capacitor for wearable applications which has been all-inkjet printed on a standard 65/35 polyester cotton textile using a new poly(4-vinylphenol) (PVP) dielectric material. Capacitors form the basis of a variety of sensors, such as for proximity and touch, as well as electronic circuits. This paper reports a general fabrication printing process to realize capacitors on textiles. The parallel plate capacitor design uses a combination of heat curable silver ink and a new UV curable dielectric ink based on PVP, printed on to the textile. This new inkjet printable dielectric ink is ultra-violet (UV) cured for 100 seconds to achieve a thin dielectric film suitable for a textile based capacitor. After printing, the dielectric properties were measured and the cross-sectional film structure was observed using an SEM. The inkjet printed PVP film on the textile exhibited good insulating behavior and similar flexibility to the original textile.