This diagram shows a new type of miniature pump activated by body heat that could be used in drug-delivery patches powered by fermentation. The micropump works by harnessing the pressure generated by fermenting yeast. Such drug-delivery patches might use arrays of "microneedles" to deliver a wider range of medications than now possible with conventional patches. (Manuel Ochoa, Purdue University). A publication-quality image is available at http://news.uns.purdue.edu/images/2012/ziaie-drugpump.jpg.