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For discoveries, inventions, and promotion of ablative photodecomposition for medical and materials applications
Rangaswamy Srinivasan ("Sri" or "Srini" to his associates) has spent his entire research career on the study of the action of ultraviolet light on organic matter. For a period of 30 years (1961 – 1990), he directed a group at the IBM T. J. Watson Research Center in Yorktown Heights, NY to investigate such interactions. When ultraviolet lasers became commercially available in the 1980s, he used the pulsed excimer laser at 193 nm for this purpose. His group found in 1980 – 83 that at this wavelength, there is a new phenomenon that leads to the etching or drilling of organic solids such as polymers (plastics) or tissue without any thermal damage to the surrounding substrate. He named this phenomenon, Ablative Photodecomposition (APD). He and his group have published 130 scientific articles and obtained 22 patents on APD. Twenty years later, APD has become the method of choice to drill polymers such as polyimide which are used in the packaging of chips and in the nozzles of ink-jet printers.
Srinivasan personally worked with surgeons to introduce APD in surgical interventions. One of the remarkable applications that has become accepted world-wide is the use of the 193 nm laser to reshape the cornea, a process known as LASIK (Laser in situ keratomileusis). Millions of people have benefited from this surgery to date. Since APD is applicable to the cutting or etching any soft tissue, other applications are also being developed such as surgery at a single cell level. Incidentally, if you are wondering why Srinivasan still wears glasses, LASIK will not work on people older than sixty – the cornea thins with age !
Srinivasan was born in India in 1929 and came to the U.S. in 1953 as a graduate student. He obtained his Ph. D. at the University of S. California and did post-doctoral work at the California Institute of Technology (1956) and at the University of Rochester (1957-61).
Many societies have honored Srinivasan for the discovery of APD. These include the American Chemical Society (Creative Invention Medal – 1997), ACS North East Section (Esselen Medal – 1997), American Physical Society (Biological Physics Prize – 1998), Inventors Hall of Fame (2002) and the U.S. Patent Office (Innovation in Technology – 2002). He was elected to the National Academy of Engineering in 1999.
Since 1990, Srinivasan has been operating a consulting company called UVTech Associates.