A novel living ink based on Saccharomyces Cerevisae for screen printing process and its applicability in producing braille text dots.

We examine the question whether a simple method of printing, the screen printing, can be adapted to print thin
layers that grow and acquire the third dimension. Therefore, we report the formulation of a distinctive living
microbes based ink suitable for screen printing process. Saccharomyces Cerevisae also known as “Baker’s yeast” is
used for the preparation of microbial ink and screen printability has been systematically developed by extensive
rheological measurements. For this, the addition of 10%, 20% and 40% w/w triton X-100 surfactant in microbial
ink is evaluated in four types of strokes (slumping, flood, mesh and squeegee) associated with screen printing
and is further linked with dynamic moduli of the inks. The microbial ink with 20% w/w surfactant shows an
optimized rheological properties desired for screen printing process. In order to demonstrate the applicability of
the formulated ink, it has been used for screen printing braille text patterns on a normal office paper. The tactile
patterns thus obtained (after growth of microbes as well as post processing treatment) are further examined for
their structural retention by load bearing characterization. Another impact of this work is that it potentially
enables inexpensive braille printing on common office paper, which otherwise is carried out on an expensive
specialized paper.