Japanese inventor Shota Ishiwatari has developed a robotic tail that tracks its wearer's heart rate and wags accordingly. Called "Tailly" — worst name ever — the venture project has its own Kickstarter campaign.
Ishiwatari has developed a prototype of the moving tail, which uses sensors on the inside of the belt to measure the user's heart rate.
According to the Tailly Kickstarter project (which appears to have ended on January 6):
Tailly is not just a toy, nor is it a fashion accessory or a gadget. It is those three items combined, and, since it reacts to the heart beat rate, an extension of the users' body. Tailly is fun to wear to parties, while out with friends or playing with kids. You could even wear Tailly on a date and express your true feelings through the wagging tail. Even better, your partner could also wear one for the both of you to add a level of subconscious communication between the two of you.
The basic color of the tail is white, but the tail is interchangeable, and we also are offering covers in Black, Gray, and Golden Brown.
"When you wear Tailly," reads the website, "you'll radiate cuteness and happiness!"
Of course, heart rate is poorly correlated with having fun or being in a good mood. A frantically wagging Tailly could also be an indication of fear or even physical exertion. But this gadget does indirectly bolster arguments for why bobbing the tail off your dog's behind is a bad idea — it's a tragic snip that makes it very difficult for your canine to properly convey its intentions and emotions.