https://en.wikipedia.org/wiki/Autopen
While visiting France, Barack Obama authorized the use of an autopen to create his signature which signed into law an extension of three provisions of the Patriot Act.[15] On January 3, 2013, he signed the extension to the Bush tax cuts, using the autopen while vacationing in Hawaii.[16] In order to sign it by the required deadline, his other alternative would have been to have had the bill flown to him overnight.[17] Republican leaders questioned whether this use of the autopen met the constitutional requirement for signing a bill into law,[18] but the validity of presidential use of an autopen had not been actually tested in court.[19] In 2005, George W. Bush asked for and received a favorable opinion from the Department of Justice regarding the constitutionality of using the autopen, but did not use it himself.[20][21][22]
