Design of a batteryless sensors supplied by ambient light with optical data transmission capabilities with application to the LiFi
A smart city is an urban area that makes use of information and communication technologies (ICT) to improve the quality of urban services or reduce their costs. It is supported on a great number of electronic sensors interconnected through a big network, namely, the Internet of Things (IoT), which collects data and provides information to effectively manage resources and assets. Since sensors must be autonomous and available for long, the use of energy harvesting techniques for supplying the sensor is being increasingly used (i.g. battery-less sensors)
In the last years, an emergent technology is being integrated to the IoT: the Li-Fi (or Light Fidelity) It is a wireless communication technology based on the use of visible light, wavelength between 480 nm (670 THz, blue-green) and 650 nm (460 THz, orange-red). While Wi-Fi uses a radio portion of the electromagnetic spectrum outside of the visible spectrum, Li-Fi uses the visible (optical) portion of the electromagnetic spectrum. The principle of Li-Fi is based on the encoding and sending of data via the amplitude modulation of the light sources (scintillation imperceptible to the eye), according to a well-defined and standardized protocol.
The objective of this project is to design a several kinds of autonomous sensors (i.g. temperature, humidity, CO…) adapted to a LiFi network and being able to transmit the information through a reversible photo-diode which is also used for collecting light energy and transforming it into electricity in order to supply the sensor.
Several blocks have to be designed and characterized: the sensors, the readout chain, the power management unit to store and regulate the harvested energy and the optical transmitter (driver).
The design must be achieved by using standard out of the shelf discrete components and/or by conceiving an Application Specific Integrated Circuit (a chip) using microelectronics techniques
-This project requires a researcher willing to deepen his knowledge on electronics and microelectronics applied to very low power and low voltage energy harvesting circuits.
-General knowledge on analog and digital electronics, particularly on the MOS transistor.
-Some familiarity with electronic circuits simulation tools (SPICE, LTspice, Cadence).
 Iskender Haydaroglu and Senol Mutlu , ‘’Optical Power Delivery and Data Transmission in a Wireless and Batteryless Microsystem Using a Single Light Emitting Diode’’, IEEE Journal of Microelectrical Mechanical systems, IEEE JSSC, VOL. 38, N° 8, pp. 1353-1363, 2003
 Bender Machado and Márcio Cherem Schneider, ‘’On the Minimum Supply Voltage for MOSFET Oscillators’’, IEEE TCAS I regular papers, 2014
 R. J. M. Vullers, R. van Schaijk, H. J. Visser, J. Penders, and C. Van Hoof, “Energy Harvesting for Autonomous Wireless Sensor Networks,” IEEE Solid-State Circuits Mag., vol. 2, no. 2, pp. 29–38, Jun. 2010, doi: 10.1109/MSSC.2010.93666