Jesse (Delve), Brian (Midwest Prototyping) and I evaluated and prototyped a bunch of approaches earlier this week including 3D printing (we have massive 3D printing capabilities).
We ended up basing our design on the face shields currently used in most hospitals (it works, very simple to make, healthcare professionals are used to it, don’t need specialized tools). We made a handful of changes / improvements listed below. So far we’re happy with this approach though we’re open to feedback. Our manufacturing partners (in one factory) could easily produce 60k shields in a day. The materials will likely cost ~dimes each until. Double and triple for additional lines and/or factories. Assembling takes less than 30 seconds per unit. We’ve already branched out from Madison and there’s definitely a factory working in Minnesota and likely one in NY very soon.
 We use adhesive-backed foam (the existing ones apply a glue / epoxy in circular patterns as shown here). Our approach removes one step in the assembly process.
 We use a latex-free elastic strap (the existing design uses a much cheaper material shown here). This increases the quality and ability to reuse if needed in urgent times.
 We extended the length of the shield by an inch or so to provide more facial protection (I can get the exact dimensional changes).
 We are using slightly thicker plastic (can get you exact dimensions if needed). This increases the quality and ability to reuse if needed in urgent times.
 We are likely to offer the shields in kit form where the hospitals do final assembly. This reduces cost and time to reach hospital. It also engages the available local workforce (a lot of single-person / social distant / task labor is available right now – which our shield is meant to be easily made by a single person). It may also make it easier to sanitize the shield once at the hospital (still TBD).
 We removed the cut-outs in the foam headband here. We found that these cut-outs were not needed and made manufacturing more complicated (time, cost).
 Still TBD: Tim Osswald is exploring the idea of changing the plastic type so it can be sanitized in an autoclave.