PMMA optical resin

Why I work with Optical Resin

I work with the optical acrylic resin PMMA rather than a silicon based material for a variety of reasons. One very important aspect of the design of my Sculpture is considering how light will travel into, through and out the sculpture. In a major sense, my work is about building a complex optical structure. And when I create these optical structures it is crucial to have the ability to design objects that do not have parallel surfaces. A sheet of optical material with a fixed thickness, for example a window in a house or a curved slumped bowl is the least interesting optically. To be optically interesting, like a prism, the surfaces need to non-parallel. Because non-parallel surfaces diverge, you are compelled to work with thick sections. PMMA allows me to construct sculpture where I am free to explore optical structures that can be measured in thicknesses of feet and potential heights in the tens of feet. If you look at silicon objects, they are predominately of a thickness measuring fractions of an inch. This is due to the inherent material properties of silicon glass.

Working with cell cast PMMA is very similar to working with clear wood. It can be bonded together and carved with carbide tipped tools. This allows for an immediacy and spontaneity to working with the material which is one of the joys of my process. The material can take on vibrant colors with the use of organic dyes.

PMMA has excellent optical clarity, better than most silicon glass and the same as optical glass. PMMA also has excellent weather-ability and has been used outdoors since the 1940's. Compared to silicon glass PMMA has ten times the impact resistance, and half the weight. PMMA has had an interesting history, first developed in 1936, it was used in WWII for submarine periscopes, gun turrets and wind shields in combat aircraft. This is where its bio-compatibility was first noted by RAF pilots whose eyes were embedded with splinters of PMMA from their shot up canopies. Since the material caused no rejection this has resulted in PMMA to be use as an implantable interocular lense in eye surgery. Practically all large Aquariums such as the Monterey Bay Aquariums use PMMA as the material of choice in large fish tanks.

Although every material scratches, scratches in PMMA are easily seen. So that PMMA should not be used in applications where it contacts an abrasive material. Scratches in PMMA can also be easily removed.

Another consideration is the environmental impact of the materials. PMMA is a carbon based material and therefore is potentially completely sustainable from plant sources and its production is not energy intensive. Compare the tremendous energy requirements of silicon glass, think of those furnaces holding materials at 2,700 degrees F and annealing ovens at 1,500 degrees F. Working with PMMA is done at room temperatures and annealed at 180 degrees F