If the waveguide is not isolated it is probably in touch with the polyimide FPCB. PI has higher RI than silicone. So to form a lossless waveguide during bending in smaller diameter you will need a low RI cladding to the silicone. Fluoropolymer is probably the only choice for silicone. Am I missing something?
1) silicone is a analogue of carbon based polymers - but the chain is of silicon atoms not carbon ones. There are many different silicones.
2) do they deposit the silicone in tracks or are they coating a whole board then etching it? I don't think 45 minute drying time is very practical if you have to deposit it as tracks, but as a board coating it might just work
With waveguides, loss-less bends can be made in case the index contrast is large enough compared to the bending radius of the bend. In the optical ray model, the total internal reflection condition is then still satisfied.
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. Are the design challenges the same as with embedded systems, but with a little developer- and IT-skills added in? What do engineers need to know? Rick Merritt talks with two experts about the tools and best options for designing IoT devices in 2016. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.