Research in smart microsensors and microsystems at Politecnico di Milano deals with several aspects of the sensor development: the materials and the physical principles, the device and electronics design, the applications. The focus is on the investigation of new concepts to enable the integration of novel and/or multiple functionalities on the same electronic system. Currently, the main topics covered by the research group are: multi-axis and multi-parameter Micro and Nano electromechanical systems (M/NEMS), other MEMS-based transducers (micromirrors, real-time clocks…), CMOS image sensors with electrically tunable spectral responses in the visible and near infrared range, the control of large integrated photonic circuits and the development of innovative integrated instrumentation for micro-nanosensors.
Most relevant research achievements
- Miniaturized inertial sensors and related readout electronics
In the framework of various scientific projects and several industrial collaborations with ST Microelectronics we have studied basic material properties (e.g. fatigue, surface adhesion phenomena, nonlinearity problems) at the micro-scale in structural materials used for the implementation of microelectromechanical systems. The results have been exploited for the design of innovative frequency modulated MEMS inertial sensors, typically subject to a large number of cycles during their life. - Development of CMOS image detector with tunable spectral responses
We have invented, designed and successfully tested a novel smart color-sensitive CMOS pixel with electrically reconfigurable spectral responses. During the development we have investigated and solved problems at the device level, demonstrated the device operation and proposed new functionalities like adaptation of the sensor to the scene, multi-spectral image capture and joint acquisition of visible and near infrared radiation. - Development of advanced miniaturized gyroscopes based on nano-structured functional elements embedded in micro-structured devices (N/MEMS)
In the frame of an international EU project (NIRVANA) this research group has in charge the design of advanced miniaturized gyroscopes in which the readout of the Coriolis force is based on the piezo-resistive properties of nano-structured functional elements. The first prototypes have been produced (at CEA-LETI Grenoble) and have been tested by the group with very satisfactory results. - Development of driving and readout electronics for MEMS/NEMS
The design of MEMS/NEMS sensors is strictly related to the design of their driving and readout electronics. The research group covers both capabilities. Several ASICs have been developed as well as electronic instrumentation for test purposes. In particular a versatile platform for the complete characterization of Micro and Nano electromechanical systems has proven to be of relevant industrial interest.
Other mixed-signal ASICs have been developed to operate MEMS-based real time clocks and MEMS-based mciromirrors. - Sensors and electronic control platforms for large integrated photonic circuits
Photonic systems can be fabricated using the same technology of the microelectronics obtaining optical integrated circuits able to process information at very high speed. The operation of such systems requires a real-time control of the working point of each optical element. To address this problem, we invented a "transparent" light sensor that allows to measure the optical power at each point of a complex integrated photonic circuit without disturbing it. Thanks to the information of the optical power, a custom control electronics, integrated on a silicon chip, stabilizes or modifies the working point of the photonic system to achieve the desired functionality. This work is currently supported by the European project H2020-ICT-STREAMS. - Integrated Instrumentation for Advanced Nano-Bio Technology
Electronics can play a key role in the research field of the nanobiotechnology and diagnostics. In this context, the research group has acquired a strong expertise in the co-design of biosensors and microchips for the detection of very small electrical signals coming by the biological world. As an example, in the framework of the European project TRAINING4CRM, neurogenerative disorders (Parkinson’s, Alzheimer's, Huntington's) are addressed using optogenetic techniques in which neuronal cells, genetically modified to be sensitive to light pulses, are implanted in the patient to replace damaged cells. Politecnico di Milano is responsible for the development of a miniaturized system to optically stimulate and electrically detect in-situ (in future directly in the human brain) the actual release of neurotransmitters by the implanted neuronal cells.