Multifunctional integrated sensor in A 2×2 mm epitaxial sealed chip operating in a wireless sensor node

We present multifunctional integrated sensors (abbreviated MFISES) that combine temperature, humidity, pressure, air speed, chemical gas, magnetic, and acceleration sensing on a single 2×2 mm chip. We fabricate MFISES in a wafer scale encapsulation process (called epi-seal) to hermetically seal the sensor functions with moving parts at low vacuum, and then surface micromachine the environmental sensors on top of the sealed layer. The encapsulation process provides very stable conditions for the pressure, magnetic, and acceleration sensors and enables the deployment of MFISES in dynamic environmental conditions without special packaging post-process. We demonstrate MFISES in a sensor node that combines energy harvesting, power management, and low power electronics to wirelessly transmit sensor data using a cloud-based service. The data can be processed and stored using server-side internet tools and then shared with any internet connected device. MFISES combined with the sensor node hardware demonstrates pivotal enabling technology in the emerging areas of wireless sensor networks and the Internet of Things.