MEMS (Micro Electro-Mechanical Systems) technology supports motion sensors that detect, report, and collect information on anything that moves. The data these sensors generate are applied to many aspects of our daily lives, ranging from necessary and practical safety standards to augmented reality entertainment. This technology is applied in many ways that can affect and enhance our daily lives.

Image by intographics from Pixabay

About Motion Sensors and IMUs

There are three sensors that detect specific types of motion: accelerometers, gyroscopes, and magnetometers.

• An accelerometer senses tilt, acceleration, vibration, and impact. With calculations and sampled measurements, acceleration measurements can be used to determine speed.
• A gyroscope senses rotation relative to an axis.
• A magnetometer detects magnetic fields on Earth. Like a compass, which also responds to magnetic fields, a magnetometer indicates which way is North.

These components are often used together either on a board or integrated in an Inertial Measurements Unit (IMU).  An IMU may comprise of two or three sensors. For example a 6-axis IMU contains a 3-axis accelerometer and a 3-axis gyroscope; adding a 3-axis magnetometer creates a 9-axis IMU

Accelerometers and Physical Safety

An accelerometer is part of many safety devices. It is often used to trigger an alarm when abrupt acceleration occurs, helping prevent physical damage. In passenger vehicles, when impact occurs beyond the designated safety threshold, airbags are quickly inflated to protect the driver and the passengers. To ensure the life-saving response is triggered the moment it is needed, high G accelerometers are used.  When a sudden change in speed occurs, the G-sensor outputs a large value that is used to invoke the necessary quick response.

Accelerometers and Maintenance

Accelerometers are also used for maintenance. With the ongoing stress of motion, when moving parts eventually become worn or misaligned a new vibration occurs. By monitoring active machinery, accelerometers detect such vibrations at an early stage, long before you can feel or see the effects of wear and tear. This capability of detecting the minute beginning of wear and tear allows lower-cost maintenance to be performed, long before significant and expensive damage occurs.

Sensors for Monitoring and Maintaining Human Health

MEMS are also used to monitor the health and wellness of people.  The use of micro-devices is growing in medical health care, which benefits the physicians and the hospital staff, as well as the patients.

For critical care, frequent checks are necessary to monitor the patient’s condition: is the patient stable, getting better, or getting worse? With micro-sized, low-power components, it becomes cost-effective to continuously gather information about the patient’s vital signs. To analyze the data from biosensors, Philips Guardian developed the Early Warning System (EWS). Vital signs are transmitted from the patient to the EWS. The information is processed with advanced algorithms that provide caregivers with the status of a patient’s current condition. When medical intervention is needed, the EWS sends an alert.

Compared to frequent and routine checks, this ongoing collection of information provides a much more detailed insight into a patient’s condition, making it possible to detect the development of problematic issues much faster and without additional effort from the medical staff.

Consumer Health Products

For those personally interested in maintaining and improving their health, many consumer products are available to monitor daily exercise: how many steps and staircases walked, pulse rate, quality of sleep, calories burned and more.  Fitbit is a popular activity-tracker that uses 3-axis accelerometers to monitor physical activities.  Some Fitbit products include micro GPS receivers that show the “map” of activity, including the pace and elevation. With Fitbit apps, the components built in a smartphone can be utilized to monitor and record basic information such as steps, distance moved that day, and the number of calories burned.

Enhanced Self Care

In addition to achieving goals in physical exercise, monitoring one’s own health has encouraged many patients to manage their care with prescribed medications on a timely basis.  Evidation Health conducted a study, and found that when using wearables and apps, patients were 1.3 times more likely to take their prescriptions on a more regular schedule. This practice is essential for chronic, life-threatening conditions such as diabetes and hypertension.

Smart Clothing

Smart clothing is available for gathering information from the electrical impulses of the human body. The textile is made of conductive fibers that are used to conduct the electrical signals, which are delivered to a module to process and transmit information. For convenience, the processing module is attached to the clothing. One such product on the market is Bioman+, which is manufactured by AiQ Smart Clothing. This high-tech apparel is available as vests, t-shirts, and sports bras. These garments are typically used for monitoring the heart rate of endurance and extreme sports participants, as well as remotely monitoring the heart conditions of patients for cardiac rehabilitation and other heart-related conditions. Like most clothing, this advanced textile is machine washable.

MEMS and Electronic Games

In the world of MEMS and wearables, high-tech gamers are a growing audience. Compared to medical devices, gaming wearables have a way to go to catch up. But they are moving forward.

Many electronic games are acquired everyday.  For example, since July 2016, over one billion apps of Pokémon Go, a mobile reality game, have been downloaded to mobile devices. Over 100 million users actively play this game every month. In this augmented reality game, images of Pokémon avatars are displayed on the game’s map on the mobile device, then players physically pursue in a virtual world that is mapped over the physical world. Pokémon Go is more than a hand-held interactive toy; it is an appealing electronic game to get people to go outside and play.

To motivate players to move their eyes away from their handheld screens, a companion device was developed: the Pokémon Go Plus that can be worn as bracelet or clipped to your clothing.  This allows users to put their smartphones into their pocket but still continue to play.

Using Bluetooth technology, this technical companion tells you where you are in the game. When you are close to a Pokémon, the bracelet vibrates and flashes light. You can then strategize how to capture that Pokémon. A non-wearable alternative is the Poké Ball, which inspires the action of throwing a ball to capture a Pokémon. The ball is not intended to be thrown; instead, the sensors within the ball measure the potential velocity, elevation, and angle based on the measurements from the player’s wrist and arm motions – the act of throwing, but not actually throwing the ball.

Total Phase and Embedded IMU Devices

MEMS devices monitor and provide data about physical movements. I2C and SPI embedded devices can be monitored, tested, and programmed with Total Phase I2C and SPI tools. Here is a video that shows how to use the Aardvark I2C/SPI Host Adapter and the Beagle I2C/SPI Protocol Analyzer to evaluate and prototype an I2C-based system that includes a 3-axis accelerometer.

If you would like more information about using Total Phase tools to develop, test and evaluate your product designs, we invite you to request a demo that is specific to your application.