Cricket: A Self-Powered Chirping Pixel

TL;DR

The paper introduces 'cricket,' a self-powered light sensor that harvests energy from light, wirelessly communicates via chirps, and can be used in various applications like solar tracking and adaptive sunglasses.

Contribution

It presents a novel, battery-free sensor that harvests light energy, communicates wirelessly through chirps, and demonstrates versatile applications including complex illumination estimation and energy-efficient lighting.

Findings

Cricket can measure light levels accurately through chirp intervals.

Miniaturized crickets require longer intervals between chirps.

Cricket-based arrays can estimate complex illumination and control lighting.

Abstract

We present a sensor that can measure light and wirelessly communicate the measurement, without the need for an external power source or a battery. Our sensor, called cricket, harvests energy from incident light. It is asleep for most of the time and transmits a short and strong radio frequency chirp when its harvested energy reaches a specific level. The carrier frequency of each cricket is fixed and reveals its identity, and the duration between consecutive chirps is a measure of the incident light level. We have characterized the radiometric response function, signal-to-noise ratio and dynamic range of cricket. We have experimentally verified that cricket can be miniaturized at the expense of increasing the duration between chirps. We show that a cube with a cricket on each of its sides can be used to estimate the centroid of any complex illumination, which has value in applications such as solar tracking. We also demonstrate the use of crickets for creating untethered sensor arrays that can produce video and control lighting for energy conservation. Finally, we modified cricket's circuit to develop battery-free electronic sunglasses that can instantly adapt to environmental illumination.