hi, this depends on the contact angle of the PR on ur substrate surface. greater contact angle give you higher sag. low surface energy substrate surface may help. Best Guocheng Shao --- On Fri, 11/13/09, Alasdair Rankinwrote: From: Alasdair Rankin Subject: Re: [mems-talk] Microlens fabrication To: "'General MEMS discussion'" Date: Friday, November 13, 2009, 2:51 AM Thanks for the note Jin. One question that keeps resurfacing for me is whether you can get hemispherical lenses from resist reflow. Most of the literature seems to show lenses with a width of say 100um but only a height of a couple microns. Is the pr reflow a reasonable means of achieving a hemispherical lens with a width of say 25 um and a height of 12-20um?