Physically Flexible Ultralow-Power Wireless Sensor

Abstract

The key challenges of local sensor networks are in supporting high sensor density, information security, physical size, and especially energy efficiency at a level that could eliminate the need for batteries or external power supplies. This article presents a novel scheme that answers all issues at the cost of minor information losses in low data rate applications that tolerate latency. Experimental verification is made using a sensor node implemented on a flexible electronics platform. Lightly encrypted data is transmitted by embedding it into Bluetooth advertising packets, contributing to ultra-low-energy wireless power consumption, and theoretically enabling an unlimited number of nodes in the local network. In the experiments the energy dissipation per transmitted 14 bytes information packet varied between 19.83 μW and 105.93 μW depending on the system configuration, while the data loss rates ranged from 7.4 % to 0.004 %, respectively. As the flexible substrate can be attached to various surfaces, the applications extend from wearable to industrial condition monitoring devices.