CC BY
11LP-I-2
Laser-induced forward transfer for paper electronics applications
P. Serra1, P. Sopeña1, J.M. Fernández-Pradas1, J. Sieiro2, J.M. López-Villegas2 1Universitat de Barcelona, Applied Physics, Barcelona, Spain
2Universitat de Barcelona, Electronic and Biomedical Engineering, Barcelona, Spain
Paper electronics represents a new concept within the broader field of printed electronics. It combines the technologies and materials employed in the fabrication of electronic devices with the use of paper as the substrate onto which the devices are supported. Paper is by far the cheapest and most widely used substrate in everyday life. In addition, it is flexible, wearable and biocompatible, not to mention that it is renewable and recyclable. All those characteristics provide paper with promising technical, economic and environmental advantages over other flexible substrates for the fabrication of devices like smart labels, RFID tags, wearable sensors or point-of-care systems in applications ranging from smart packaging or health care to safety.
In this work we prove the feasibility of laser-induced forward transfer (LIFT) for printing electronic devices on cellulose paper. Unlike inkjet printing, its major digital competitor, LIFT is a technique with few restrictions concerning the rheological properties of the printable inks. This makes this technique specially suited for printing high solid content inks, an important requirement in the fabrication of conductive pads: the low sheet resistances needed can hardly be achieved with the typical low solid contents of inkjet printing inks. For paper electronics there is an additional advantage: it is possible to print on regular paper. Thanks to the high viscosity of high solid content inks there is no need to submit the substrates to the planarization treatments so characteristic of inkjet printing on paper, and thus minimize the use of additives, with the benefits that this represents both in terms of cost and impact on the environment.
