Making sense of sensors: what you don't know your phone knows about you

What do all of the sensors in your phone do, and what's coming in the near future?

"It would be great to have air and water quality sensors, some forms of medical sensing, 3D/stereo cameras, even radar and sonar... the wishlist could certainly grow if we could have an understanding of how quickly sensor miniaturisation will proceed."

Sensory overload

How would you like a phone that could track your heart rate and emotional state, perhaps putting on some soothing music as soon as you start to get anxious?

According to Freescale Semiconductor director Kaivan Karimi, this is possible using sensors that cost just a few pounds.

"Your device will get to read your emotions," Karimi told the GigaOM Mobilize Conference in October. "That means you can track people's emotions remotely... your device will know you significantly better than you do."

The microelectromechanical systems (MEMS) built into our phones are made of silicon, but scientists are now experimenting with MEMS running on an organic polymer more suitable for implanting in the human body.

Once the cost and time taken to manufacture these components comes down, we could be able to monitor health and activity from inside our own bodies. They could even be used to control bionic limbs.

Skin sensor
With implanted sensors, you can get readouts on your current health and fitness.

UV light sensors are also in the stages of early testing by manufacturers including ROHM. Find out how much sun cream you need, or how clean your hands really are, or how much you've had to drink, all courtesy of your phone.

Imagine the difference it would make to a check up at the doctor's if you had two months' worth of data on file rather than relying on your own memory and a quick five minute conversation.

On a broader level, disease and health patterns can be tracked more accurately across countries and continents.

Researchers at the University of California, Berkeley have built a working prototype of a pollution sensor small enough to fit inside a mobile phone, giving governments and health officials the opportunity to measure smog and dangerous chemicals across cities (as well as giving you a warning when it's time to don a face mask). Mobile air monitoring sensors are also being developed by the US Environmental Protection Agency.

Credit William Griswold Jacobs School of Engineering at UC San Diego
Don't forget your face mask...

Meanwhile, Antonio D'Alessandro and Giuseppe D'Anna, seismologists at the National Institute of Geophysics and Volcanology in Italy, have run tests on the iPhone 4 and 5 to demonstrate how mobile phones could be used to detect earthquakes.

The sensors within our handsets need to improve, but eventually they could act as early warning systems and get aid to those in need more quickly.

Next-generation sensors will make a difference on a local and a global scale. AT&T's Emiliano Miluzzo again: "By turning a smartphone into the equivalent of a Swiss Army knife, we could change lives in both high-tech and developing countries because what people need would be in the palm of their hands anytime and anywhere.

"Not only will users get immediate answers to their problems, but governments too will be able to run their infrastructures more efficiently."

"Medical data could be continuously streamed back to the cloud," continues Miluzzo. "If something was flagged as anomalous, it would trigger an alert for medical intervention.

"Governments could rely on crowdsourced 24/7 pollution level measurements, people in developing countries could rapidly check the quality of their water, EEG headsets could let people control their devices simply through their thoughts, and radar and sonar sensing could let people be more aware of their surroundings."

The smarter home

As sensors become smarter, so will all of the other gadgets and equipment in our homes. The sensor-packed smartphone of the future won't work in isolation, but as part of a larger network of devices, whether it's the thermostat at home or the Wi-Fi enabled lamppost out on the street, each with their own integrated miniature monitoring components.