More MEMS Integration: Into Sensors, Systems, and Humans



Humans will touch, move and interact with MEMS as part of the exploding Internet of Things.

For a technology that doesn’t follow Moore’s Law, the state of MEMS changes rapidly. One hot trend is how easily MEMS devices integrate into complete sensors, then into whole systems complete with processors and software. The machine-to-machine (M2M) cloud and Internet of Things are driving MEMS with standard interfaces such as I2C and SPI, available Linux and Windows 8 drivers, and integrated MCUs. This trend is moving MEMS closer to integration into things we wear and use.

IHS iSupply ranks MEMS supplier STMicroelectronics as the world’s largest MEMS supplier, having all manner of discrete MEMS devices including magnetometers, gyroscopes, accelerometers, pressure sensors, temperature and humidity MEMS, and mobile moving projectors. Armed with this vast portfolio, ST, like its competitor Freescale, is combining different devices together to create standalone MEMS sensors.

Combining a gyro with an accelerometer and a magnetometer creates a MEMS sensor ideal for indoor positioning. This kind of sensor, says Fabio Pasolini, GM of ST’s Motion MEMS Group, only needs to add some external processing to become a standalone navigation subsystem. Freescale also sees this sensing system trend and the company is looking to combine accelerometers with gyroscopes to provide drift-free sensors.

To make those sensors more useful to designers who are increasingly focused on the end human, ST and Freescale are adding standard interfaces such as I2C or SPI. This abstracts the MEMS device completely: the application developer need only treat the MEMS output like any other I/O. Vendors are going one step further, however, and making software drivers available for many of their most popular sensors. The smartphone trend prompted ST to make available drivers in the 3.9 and newer Linux kernels, and the next version of Android is rumored to include drivers for popular ST and Freescale MEMS sensors. Michelle Kelsey, product line manager for Sensors, says Freescale has also provided Windows 8 drivers for some of its sensors. With the driver already in the OS, apps developers need only worry about the output from the sensor…not how to deal with raw data.

Still, designers want more. Both ST and Freescale are fusing some of their MEMS sensors with popular MCUs to create context-aware subsystems. The sensor can provide data (from accelerometer, gyro, compass, pressure, etc.) and the MCU can sort through it all to provide context-aware sensor information. The subsystem, for instance, no longer spews all manner of noisy (excess) position or pressure data when all the higher-order system really wants to know is an exact location, or if the pressure and humidity have changed from baseline. Freescale’s MMA955xL device combines a Coldfire PowerPC with MEMS sensor; ST’s iNEMO inertial modules combine 6 to 9 degree-of-freedom sensors with STM32 MCUs.

All this intelligent MEMS integration is creating fascinating new products that we use and wear. ST demoed iNEMO at CES 2013 integrated into shoes that measured location and speed, harvested kinetic energy and transmitted telemetry data. Sports accessories such as the Nike FuelBand or Fitbit FLEX could be drastically enhanced with more sensor fusion (blood pressure, O2 stats, air quality, ambient lighting). Augmented reality proof products like Google Glass could adapt the environment to the user (not the other way around) while measuring inter-ocular (eye) pressure looking for glaucoma, noticing a left-on gas stove burner, or sampling the air for too-high CO or radon levels.

 


ciufo_chris

Chris A. Ciufo is Editor-in-Chief for embedded content at Extension Media, which includes the EECatalog print and digital publications and website, Embedded Intel® Solutions, and other related blogs and embedded channels. He has 29 years of embedded technology experience, and has degrees in electrical engineering, and in materials science, emphasizing solid state physics. He can be reached at cciufo@extensionmedia.com.

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