DARPA develops chip for navigation without GPS

Defense Advanced Research Projects Agency (DARPA) researchers have been developing a timing and inertial measurement unit (TIMU) that contains everything needed to aid navigation when GPS is temporarily unavailable.

The single-chip TIMU prototype contains a six-axis IMU (three gyroscopes and three accelerometers) and integrates a highly accurate master clock into a single miniature system, smaller than the size of a coin. This chip integrates breakthrough devices (clocks, gyroscopes and accelerometers), materials and designs from DARPA’s Micro-Technology for Positioning, Navigation and Timing (Micro-PNT) program.

Three pieces of information are needed to navigate between known points ‘A’ and ‘B’ with precision: orientation, acceleration and time. The new chip integrates devices that can measure all three simultaneously. This elegant design is accomplished through new fabrication processes in high-quality materials for multilayered, packaged inertial sensors and a timing unit, all in a tiny 10 mm³ package. Each of the six microfabricated layers of the TIMU is only 50 µm thick, approximately the thickness of a human hair. Each layer has a different function, akin to floors in a building.

“Both the structural layer of the sensors and the integrated package are made of silica,” said Andrei Shkel, DARPA program manager. “The hardness and the high-performance material properties of silica make it the material of choice for integrating all of these devices into a miniature package. The resulting TIMU is small enough and should be robust enough for applications (when GPS is unavailable or limited for a short period of time) such as personnel tracking, handheld navigation, small diameter munitions and small airborne platforms.”

The goal of the Micro-PNT program is to develop technology for self-contained, chip-scale inertial navigation and precision guidance. Other recent breakthroughs from Micro-PNT include new microfabrication methods and materials for inertial sensors.