Once we control e-paper, we need to send data – image and content – to the display. Lummico typically does it via NFC. NFC belongs to the RFID family, i.e. contactless cards, wireless payments, short-range communication. And just like a payment card, it does not have a battery inside, but it communicates while taking energy from the reader or phone. You hold a card close to a reader, the card wakes up, takes energy from the reader and they exchange data. It is quite simple because the energy needs of a card are negligible, however, when it comes to refreshing e-paper, it is not so, we need more energy (but still relatively little of it when compared to an LCD or a TFT display). Therefore, we have this dilemma whether to transmit energy or transmit data. Lummico solved the dilemma very efficiently. The energy is controlled all the time and the data is sent in between the transfers of energy. This is done by the software on the reader’s side; a mobile phone or a tag, that receives the data. Building all this is not so easy, but once done, we have a batteryless tag. Such a tag is basically dead, nothing happens to it until we bring a reader or a mobile phone in to pass energy. It is a great, eco-friendly solution.