Applications of RF-powered computing systems: Wearable EEG monitor and bistable display tag.

摘要

The advances in electronics reduced the energy requirements for computation and sensing to an extent needed to enable RF-powered systems. We demonstrate that it is possible to build key components of a ubiquitous computing system in a RF-powered way: sensing (input) and output. Those systems were built using software defined passive radio frequency identification (RFID) tags.;As an input application, we demonstrate the EEGWISP: battery-free electroencephalogram (EEG), which uses RFID for power and communications. The wearable EEG monitoring systems are the cornerstone of noninvasive brain-computer interfaces (BCI) and many medical applications, but state-of-the-art wearable systems are limited by weight, battery life and size. Since EEGWISP does not need batteries it can be lightweight, miniature and maintenance free for users. For the output application we developed a bistable display tag that, from an energy standpoint, is capable of perpetual operation. A commercial off-the-shelf NFC-enabled phone generates RF signals carrying both the information and energy necessary to update the display. After the update is complete, the display continues to present the information with no further power input. We present one example implementation, a companion display for a mobile phone that can be used to capture and preserve a screenshot.