Printable IoT sensor development platform

This technology is a new sensor made up of dielectric materials tuned to accurately measure a variable and wide range of temperatures. The sensor is wireless and is powered by an external magnetic field. As the temperature changes, the dielectric material changes its signature magnetic response and the change is detected by a magnetic field response sensor. Applications for this technology are temperature sensors for non-conductive surfaces where the conditions or operations require a robust and wireless sensor.

With a form factor close to a deck of playing cards, the system interrogator has custom software to interface with and service a population of sensor tags at the required data rates. Each EPCglobal C1G2 sensor tag uses incident interrogator energy to charge its small integrated circuit (IC), which reads an internal memory bank, encodes identification data, and uses that information to modulate and backscatter a reply to the interrogator using reflected interrogator energy. Two tag interfaces allow the attached processor to power the reading/writing of data to the tag memory and then allows the interrogator to power the reading of the tag memory data. When neither of the two interfaces are engaged, the RFID IC is completely powered down. Reading and writing tag memory consumes relatively little power compared to the power draw of active transmitter/receiver protocols like Bluetooth, Zigbee, and Wi-Fi. Compared to passive sensing protocols, this wireless instrumentation system enables sampling of a larger population of tags without the computational burden associated with surface acoustic wave (SAW) sensing. RFID-Enabled Wireless Instrumentation technology allows the RFID interrogator to write data through the interface of a sensor tag memory bank using only interrogator power. With only minimal cost to the sensors power budget, the microcontroller unit can read that data out over the serial interface. The sensor can transmit and receive data at no effective cost to its small coin cell battery power supply. This technology is readiness level (TRL) 8 (actual system completed and "flight qualified" through test and demonstration) and the innovation is now available for your company to license. Please note that NASA does not manufacture products itself for commercial sale.

Glenn's breakthrough technology introduces batch-fabricated, miniature sensors embedded and distributed over a large surface area of a material or product during the manufacturing process. The sensors can be utilized for test instrumentation or as an integrated in-situ monitoring system. This integrated manufacturing approach preserves the structural and mechanical system integrity by eliminating the antiquated plug-in approach, invasive machining, manual insertion, and gluing processes currently required to implant sensors into a material. The sensor ladder network of resistors and capacitors breaks down as result of the thermo-physical effects caused by temperature, shock, radiation, corrosion, or other reactions, causing a change in the electrical properties. A processor interprets these changes in the electrical properties and generates a high-resolution, large-area surface profile. The profile demonstrates the amount or rate of material deterioration and temperature change, and is used to optimize geometric structural design, develop materials, predict performance, and make decisions. These sensors play an important role as industries work to realize material performance and product design. This type of monitoring is ideal for infrastructures, nuclear enclosures, or any system susceptible to surface deterioration.

Conventional ambient-temperature oxygen sensors are limited in various ways: optically based sensors can be expensive and challenging to manufacture; electrochemical cells with liquid electrolytes can have limited lifetimes and become leak sources; and both types of sensors are difficult to miniaturize. These problems are addressed with Glenn's novel ambient temperature oxygen microsensor, which is based on a Nafiontm polymer electrolyte, microfabricated using thin-film technologies. In the past, one drawback of Nafiontm film has been that it can lose conductivity when the moisture content in the film is too low, potentially affecting sensor operation. Glenn researchers devised a method to use certain salts to hold water molecules in the Nafiontm film structure at room temperature. The presence of these salts provides extra sites in the film to promote proton (H+) mobility, thus improving film conductivity and overall sensor performance, particularly in arid and high-temperature environments. The innovative use of metal/metal oxide as the reference electrode enables miniaturization by eliminating the reference gas and sealing the reference electrode. The combination of interdigitized electrodes with the unique metal/metal oxide reference electrode permits sensor operation in either potentiometric or amperometric mode, as appropriate. In potentiometric mode, which measures voltage differences between working and reference electrodes in different gases, the voltage differences can be monitored with a voltmeter; however, the sensor itself does not need a power source. In room-temperature testing, the sensor achieved repeatable responses to 21 percent oxygen in nitrogen (using nitrogen as a baseline gas), and also detected oxygen from 7 to 21 percent, making Glenn's breakthrough technology usable for personal health monitoring as well as fire detection, fuel-leak detection, and environmental monitoring.

The low-profile sensor is configured with a spiral electrical trace on flexible substrate. In typical inductor designs, the space between traces is designed to minimize parasitic conductance to reduce the impact of the capacitance to neighboring electronics. In the low-profile sensor, however, greater capacitance is desired to allow the operation of an inductor-capacitor circuit. This allows the traces to be closer together, decreasing the overall size of the spiral trace. The sensor receives a signal from the accompanying magnetic field data acquisition system. Once electrically active, the sensor produces its own harmonic magnetic field as the inductor stores and releases magnetic energy. The antenna of the measurement acquisition system is switched from a transmitting to a receiving mode to acquire the magnetic-field response of the sensor. The magnetic-field response attributes of frequency, amplitude, and bandwidth of the inductor correspond to the physical property states measured by the sensor. The received response is correlated to calibration data to determine the physical property measurement. When multiple sensors are inductively coupled, the data acquisition system needs to activate and read only one sensor to obtain measurement data from all of them.