It’s a challenge every startup faces: they’ve made a prototype and proven the thing works, but now have to sell the product and produce enough to get past the “ valley of death ” that kills so many companies. “They are chicken and egg stuck,” Josh Felser, co-founder and managing partner of early-stage venture firm Climactic , told TechCrunch. The hurdle is particularly high for companies making physical goods. Felser noticed it was a common occurrence among startups producing novel materials.