A Wireless Sensing Platform for Every Surface—Boeing’s Condition Monitoring Sensor Array
As part of the NextFlex Consortium and the prime partner for the Condition Monitoring Sensor Array (CMSA) project, Boeing Research, and Technologies’ Additive Electronics Technology (AET) group has been working to advance the technology and manufacturability for Flexible Hybrid Electronics (FHE) associated with wireless sensing. The CMSA project has an overall objective of providing a bendable, flexible, adaptable sensor system that enables an end-user to select sensors, measurement functions, communication links, and operational modes on a platform that is independent of wired connections for power and data transfer. The sensor array is composed of various components and materials. Clear Polyethylene Terephthalate (PET) is used as the substrate with conductive inks for the traces that connect the various components. A Nordic BLE transceiver, in the form of a thinned processor on an interposer, servers as the system on chip for the platform. The processor and various passives are attached with anisotropic conductive paste (ACP) or fast curing conductive epoxies. Various printed sensors, such as temperature, humidity, strain, and pressure are used to determine the current environment. An irreversible indicator is used to show when the battery has been depleted. Communication off the platform is accomplished with a Bluetooth Low Energy (BLE) protocol using a printed antenna. And finally, the platform is powered with a flexible battery. Once the platform is placed on a surface and powered on, the sensors automatically acquire data at periodic intervals and a user has the option to pull data off the platform periodically or adjust the cadence of sensor measurements over a BLE link to a smartphone. The platform is inherently flexible, both in form and function, making it easy to apply to a non-conformal surface and other applications beyond the sensors previously listed.