Haptic feedback is attractive for all kinds of man-machine interfaces and gaming. It is a touch sensation generated in the human skin by a modulated and focused ultrasound (US) beam. To generate such a beam, large US transducers in TFT technology are needed. Driving these arrays is a circuit design challenge taken up by MICAS. In 2023, we published two driver arrays dealing with all the challenging circuits aspects in different TFT technologies. Power efficiency enhancement with advanced charge recycling and novel synchronization techniques are the most striking examples. The required synchronization accuracy goes beyond what is achievable in TFT technology. This led to the development of a hybrid/TFT architecture with a current based interfacing technique to exploit the capabilities of both technologies. The design of hybrid Si/TFT circuits is a topic we will further work on in our future research.
An Ultrasonic Driver Array in Metal-Oxide Thin-Film Technology Using a Hybrid TFT-Si DLL Locking Architecture; Jonas Pelgrims, Kris Myny, and Wim Dehaene; IEEE Journal Of Solid-State Circuits; 2024; Vol. 59; iss. 2; pp. 516 - 527