I wonder how soon this will be developed in large quantities. Funding from places like Bill Gates' foundation is almost certain, but there seems to be a lag, as

I wonder how soon this will be developed in large quantities. Funding from places like Bill Gates' foundation is almost certain, but there seems to be a lag, as the TED talk is from June 2012, while the arXiv paper [1] as well as the linked post from March 2014. Maybe hitting the 50¢ mark would require lots of units? [1] http://arxiv.org/abs/1403.1211 http://arxiv.org/abs/1403.1211