Touchcode uses conductive ink to bridge the gap between the physical and digital worlds via: 1) an invisible identification tag that can be printed on packaging and connect physical and off-shelf products to a digital experience, and 2) an after-market retail shelf that is able to track product inventory in real time.

Matt’s TL;DR: i love the conductive ink as a trigger for smartphones once their lightweight SDK is in your app. Beats QR codes and even NFC! While they are focused on marketing activations, I see much more potential in using this for Digital Product Passports.