There are at least two big challenges with creating wearable technology. The first is to actually design something that people will want to buy and use, and the second is to keep the device in juice. Here we're going to look at the second.

The battery design and function of a wearable device is anything but trivial. We need to develop batteries that are flexible, thin, long-lasting and durable...a huge set of requirements that is very difficult to achieve. But one startup, Imprint Energy, thinks it's got a leg up with a printable, durable battery.Just for background: Batteries that power a lot of our current tech (i.e., laptops, smartphones) contain lithium, which is pretty delicate and needs protection making such batteries relatively bulky. Zinc has been a more stable option, touted as a suitable substitute but they are not ultimately the most durable. This new material is formed with a polymer electrolyte, trademarked as ZincPoly, that apparently gives the zinc durability, stability and has a greater capacity overall.

The flexibility and tiny size make it great for product designs that are simply impossible with lithium batteries. Right now, Imprint's battery can withstand 1,000 bending cycles making it the most stable of the so-called flexible batteries, by far. They are rechargeable and cheap to manufacture because they can be printed on industrial screen printers.

The plan is to have the batteries power wearable electronics, medical devices and any other small sensors. Apparently they can supply enough power for wireless communication as well-something that has eluded other small flexible batteries. Imprint's founders say that their batteries are safe for clothing that is close to the body, or even for potential medical sensors that can monitor one's health.

Last month, the startup secured $6 mil in Series A funding led by Phoenix Venture Partners and with Flextronics Lab IX and AME Cloud Ventures. This ZincPoly technology is something worth keeping an eye on as wearables and the Internet of Things reach mainstream.