Inkjet printed flexible antenna on textile for wearable applications

We report a direct write inkjet printing technique for fabricating a flexible antenna on textile for use in smart textile applications such as wearable systems (Rienzo et al. 2006). The complete antenna was deposited entirely using inkjet printing. The inkjet printed antenna is based on a half wavelength dipole antenna offering a planar structure and acceptable size. The printable silver nanoparticle-based conductive inkjet ink has a curing temperature of 150 o C for 10 minutes or 130 o C for 15 minutes. The theoretical designed peak frequency of the antenna is 2.4 GHz. The entire antenna is directly inkjet printed on three difference substrates; 1) Kapton, 2) polyurethane (PU) coated stretchable textile and 3) pre-treated 65/35 polyester/cotton textile. The difficulty realizing an inkjet printed antenna on the three substrates increases with each substrate since each has increasing surface roughness. All three antennae on the three different substrates show a similar peak operating frequency and impedance output characteristic. The principle of a stretchable antenna is investigated by inkjet printing the conductive silver ink on a pre-