US Patent 7681301 - Silicon nanostructure RFID antenna

http://www.freepatentsonline.com/7681301.html

This patent teaches a laser ablation method to generate microscopic spikes on the surface of bulk silicon used for an RFID antenna. Claim 1 reads:

1. A method of producing a Radio Frequency Identification (RFID) antenna as an integral part of an RFID integrated circuit using silicon as antenna material thereby enabling the antenna and an RFID integrated circuit to be manufactured as one piece, said method comprising:

providing commercially produced bulk sheets of silicon wafer base material (silicon wafers);

femtosecond laser ablating, with a sharply focused pulse, the silicon wafers to create three dimensional nano structures out of the silicon base material;

designing an antenna as a complex resonant antenna at a macro level and reducing it, through a process of de-magnification or photographically, to a nano sized image which perfectly replicates design features of a macro level template directional antenna on a master stencil mask and, still further, forming this master stencil mask on the reverse side of silicon wafers treated with femtosecond laser ablation;

manufacturing said femtosecond laser ablated silicon wafers so that they are manufactured into radio frequency identification antennas.