Opal glass would provide excellent diffusion (producing a Lambertian distribution of the light source), but might be difficult to work with in your lamps. You might try a fabric shop for translucent synthetic fabrics, a photo shop for diffusion film, or Amazon (see http://www.amazon.com/Rosco-Roscolux-Diffusion-Diffusing-Material/dp/B000B73OQY) for some material used in theater lighting.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.