You can perform this sort of measurement very inexpensively using a home-made levered laser setup. This is accomplished by reflecting a laser beam off the sample as it is moved on a linear trasnlation stage. The radius of curvature of the sample can be calculated as a function of the displacement of the laser spot on a screen (which may consist of a sheet of graph paper), verses the translation distance of the sample. The technique is discussed by Sinha, Levinstein, and Smith: Thermal stresses and cracking resistance of dielectric films (SiN, Si3N4, and SiO2) on Si Substrates J. Appl. Phys, Vol 49, No 4, April 1978. Roger Shile l>>> henryang@us.ibm.com 04/08/02 03:41PM >>> Hi David, I don't know if there is a non-contact equipment around Boston you can use. I'm guessing you don't have a Flexus. The dimensions you mentioned can be measured comfortably in a Flexus system. If the deflection is large enough, you might be able to get away with anchoring one end of your sample and measure the deflection on the other end using a microscope. That will at least give you a stress delta. Good luck! Henry "David Tang"@memsnet.org on 04/04/2002 05:33:00 PM Please respond to mems-talk@memsnet.org Sent by: mems-talk-admin@memsnet.org To: cc: Subject: [mems-talk] radius of curvature measurement Hello, I am trying to characterize thin film material properties by measuring the radius of curvature of specimens that are ~1cmx10cm long. Does anyone know of vendors/labs/universities around Boston that have non-contact equipment to measure radius of curvature? Thanks. David Tang MEMSIC Inc. 100 Burtt Road Andover, MA 01810 Phone: 978-623-8188 x 237 www.memsic.com _______________________________________________ mems-talk@memsnet.org mailing list: to unsubscribe or change your list options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk Hosted by the MEMS Exchange, providers of MEMS processing services. Visit us at http://www.mems-exchange.org/ _______________________________________________ mems-talk@memsnet.org mailing list: to unsubscribe or change your list options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk Hosted by the MEMS Exchange, providers of MEMS processing services. Visit us at http://www.mems-exchange.org/