IDBR: Encounternet: Ultra-Miniature Energy Harvesting MEMS-Based Tags Enabling New Social Network Research

University Of Washington, Seattle WA

Investigators

Abstract

All animal societies can be viewed as networks of interconnected individuals, linked by social, spatial, temporal, and other relationships. By studying the links of association between individuals we can derive unique insights into the workings of the society, and better understand the various behavioral strategies that individuals use to enhance their success. The study of animal social networks requires that associations between individuals be continuously monitored for extended periods of time. The task of determining social associations and movement patterns is usually attempted via direct observation methods. However, in many cases, observation is not feasible, especially when animals must be continuously monitored for long periods of time, when animals behave cryptically (as they often do), or when animals are out of sight of observers. The Encounternet project will result in a miniaturized tag device for social network and behavioral studies. This microprocessor-based digital radio tag technology allows autonomous monitoring of the proximity of each tagged animal to all other nearby tagged individuals on a continuous basis. Encounternet consists of two components: small groving node transceiver tags mounted on animals, and collection node devices placed at fixed locations in the field. The roving node tags will weigh approximately 1g, allowing placement on small animals such as song birds, rodents, and reptiles, and will employ energy harvesting technology to extend their lifespan. To achieve the desired encounter monitoring functionality and enable a significant improvement in miniaturization, Encounternet will utilize integrated circuit advances in wireless transceivers, a new social network monitoring radio protocol design, and an energy harvesting low voltage solar powertrain to augment battery power. For behavioral recording, Encounternet tags can be equipped with a variety of sensors, including accelerometers, microphones, and light monitors. Sensor-equipped tags can be configured to wirelessly stream sensor data to a receiver or store it in onboard non-volatile memory for later retrieval. This technology allows researchers to acquire an enormous amount of rich information about study animals, their spatial movement patterns, behavior, even physiological state, which would be impossible to acquire using conventional analog tracking technology, allowing animal movements, social association, and behavior to be monitored on a continuous basis for the entire study period. The development of Encounternet will promote outreach in the following ways. A prototype network will be deployed in field tests with various collaborators who study animal social behavior. Although Encounternet is intended for small animal social network research, it can be applied to a wide variety of applications, including disease vector species interaction, below-ground social interactions in fossorial species, and spatial/temporal decision making processes in herds and flocks. Tours of the Discovery Park (Seattle, WA) prototype deployment will be given to groups of high-school students to promote interest in both technology and nature.