Taking sensors in a new direction
By applying microsystem technologies to sensors, the IMuTS team is developing a suite of ultrasensitive sensors to measure diverse phenomena including light direction, acceleration waves, ambient gas concentrations, and angular rate, along with micromechanical oscillators for telecommunications.
Among the group’s inventions is a first-of-its-kind vector light sensor that – unlike typical sensors – tracks light source as well as light intensity. Using triangulation, two sensors can then estimate distance to a light source. This has important applications, says Bahreyni, because humans and other warm-blooded animals radiate infrared light.
So, by fine-tuning the sensors to respond to infrared, it is possible to track humans for improved safety – for example, in factories where humans and heavy machinery co-operate – or for use in consumer electronics such as mobile devices.
Placed in an array, the sensors can take images to a whole new dimension, capturing both depth perception and a light intensity map. A 3D image, in other words. This is groundbreaking, explains Bahreyni, because two cameras are normally required to create 3D images; each lens capturing the subject from a slightly different perspective to create a sense of depth.
“The sensor array is less than a millimeter in thickness, but will be able to focus onto any object in the field without using optical lenses,” says Bahreyni.
“It’s all about taking signal processing from an optical domain to a digital domain." The new sensors could find use in tiny lens-free cameras that could be embedded in all kinds of things, from wearable consumer gadgets to security systems.
In addition, Bahreyni’s team is developing microsensors to detect sound direction. Current systems use large arrays of microphones to map variations of sound to derive sound direction. The IMuTS lab instead is developing devices to measure sound pressure and direction simultaneously with ultrasensitive accelerometers.
The accelerometers under development at the IMuTS lab are approximately 1000 times more sensitive than micro-accelerometers currently used for crash detection in vehicle airbag deployment systems, and orientation detection in mobile devices. As a result, they can detect movements as small as 1pm (that is 1/100th of a hydrogen atom diameter) across the audio band. The research will provide novel solutions for many applications ranging from geophysical studies to border security.