Mobile phones have come a long way since the first mass-produced handheld mobile phone was introduced in 1973. Here, we discuss the smartphone sensors currently incorporated in smartphones and look at where technological advancements in this sector may go and what challenges they may face. Finally, we make some estimations about the future of smartphone sensor technology.
Image Credit: Akhenaton Images/Shutterstock.com
For the first few decades, these devices were only able to make calls and were generally only owned by the wealthy. In 1992, the world's first SMS message was sent, which read "Merry Christmas" and was sent by a developer at Vodafone to his director. In the same year, what is considered the world's first smartphone was launched.
The 'Simon' by IBM, could send and receive emails, faxes, and pages as well as making calls. Ownership of a smartphone remained relatively low throughout the 1990s, with current ownership rates reaching an all-time high of more than 80%.
Part of the reason that smartphones have experienced a rapid boost in popularity is due to the sensor technology it incorporates. Now, smartphones can accomplish the jobs of dozens of gadgets with the help of this technology. Phones act as pedometers, inform users of the weather, provide navigation purposes while walking, driving, and cycling, and use environmental sensors to protect the device and ensure its durability and longevity.
What Sensors are Currently Used in Smartphones?
There are currently a number of smartphone sensors that are incorporated into almost every smartphone device. Motions sensors, for example, are a staple of smartphone technology. They measure the user's acceleration, movement, speed of revolution, drift, and curl vector values to gain an understanding of the movement of the device in real-time. Motion sensor technology is based on the gyroscope, incorporating multiple sensors into one.
Gravity sensors can measure gravity's direction and intensity, allowing the smartphone to calculate the device's relative direction in space. Gravity sensors are relied on by navigation applications that track the movements of a car.
Curve vector sensors are also required to measure the direction of a device. These sensors detect the slop of the device. Applications that measure the number of steps walked (e.g. exercise applications) rely on the information collected by curve vector sensors, often alongside an acceleration sensor and a gyroscope.
The location sensor is responsible for reporting the physical location of the device. This technology uses a geomagnetic sensor alongside an accelerometer to determine the smartphone's relative location from the North pole; they are also coupled with GPS sensors to give accurate location information. Location sensor technology can also be used to ascertain how far the user's head is from the headset, allowing the phone to understand the user's proximity, turning the screen off when not in use, and being inactive during a call.
What Sensors Are in a Smartphone?
Video Credit: Scientific American/YouTube.com
A smartphone's compass is powered by its magnetometer, a type of sensor capable of measuring magnetic fields, allowing the phone to identify north.
In recent years, image sensors have become increasingly important when developing new smartphones. Consumers demand better and better image quality from their cameraphone photos. While large megapixel counts are important to this, large image sensors are possibly equally important as they allow more light into the picture, resulting in higher quality images.
Finally, smartphones incorporate four types of environmental sensors to measure humidity, illumination intensity, surrounding pressure, and temperature. More accurately, illumination intensity sensors exist in the form of an ambient light sensor, a type of photodetector that can measure the amount of ambient light surrounding the device. Together, these sensors protect the smartphone from overheating and automatically adjust the screen brightness.
Current Developments In Smartphone Sensor Technology
One promising area of smartphone sensor development is in the use of these sensors for monitoring and recognizing diseases. As life expectancies rise across the world, as does the aging population and the costs associated with their healthcare, smartphones offer a valuable route to obtaining data from continuous monitoring.
Given that many diseases related to the cardiovascular system are associated with the eye, respiratory system, and skin, scientists are currently developing sensors that could be incorporated into smartphones to collect data from these sources.
Future Outlooks of Sensors for Smartphones
It is likely that sensor technology will continue to develop to grow the functionality of smartphones.
Currently, research that is developing smartphone sensors to monitor health is still in its early stages. Scientists must enhance the accuracy of data collected from these sensors plus design sophisticated analytical systems capable of automatically processing vast amounts of data with high levels of accuracy. It will likely be several more years before such sensors can be incorporated into phones that are widely available.
References and Further Reading
Cho, A. (2020) What Kinds of Sensors are Embedded in Smartphones? [Online]. Samsung SDS. Available at: https://www.samsungsds.com/en/story/What-Kinds-of-Sensors-are-Embedded-in-Smartphones.html
David Nield. (2020). All the Sensors in Your Smartphone, and How They Work. [Online]. Gizmodo. Available at: https://gizmodo.com/all-the-sensors-in-your-smartphone-and-how-they-work-1797121002
Majumder, S. and Deen, M., (2019) Smartphone Sensors for Health Monitoring and Diagnosis. Sensors, 19(9), p.2164. Available at: https://dx.doi.org/10.3390%2Fs19092164
Tweedie, S. (2015) The world's first smartphone, Simon, was created 15 years before the iPhone. [Online]. Insider. Available at: https://www.businessinsider.com/worlds-first-smartphone-simon-launched-before-iphone-2015-6?r=US&IR=T (Accessed 11 October 2021)