MSc thesis project proposal

[2022] A wearable ultrasonic vagus nerve stimulator

Ultrasonic vagus nerve stimulation (uVNS) [1] is a promising alternative to traditional VNS based on electrical stimulation (eVNS) [2]. While eVNS requires a surgical procedure to implant a cuff electrode and a programmable stimulator, which is not without risks and can lead to side-effects, uVNS has the potential to be able to achieve similar spatial resolution while remaining non-invasive. However, existing uVNS devices either rely on single-element focused transducers [3], which require motorized stages for precise targeting of the nerve, or are still too bulky to allow for a complete wearable system in small-animal studies [4]

This project aims at developing a miniaturized and wearable uVNS device. It will consist on the microfabrication of 2D arrays of PMN-PT ultrasound transducers, and interfacing the array with the Verasonics Vantage 256 research system, which is available in the Microelectronics Biosonic Lab. For the microfabrication, the candidate will follow our previous work [4,5], and use a state-of-the-art dicing saw tool, which is the newest addition to the Biosonic Lab. Pending on the achieved progress, there is the possibility to test the prototype with animal models in vivo.



1.   Wasilczuk KM, Bayer KC, Somann JP, Albors GO, Sturgis J, Lyle LT, Robinson JP, Irazoqui PP. Modulating the Inflammatory Reflex in Rats Using Low-Intensity Focused Ultrasound Stimulation of the Vagus Nerve. Ultrasound Med Biol. 2019 

2.   R. L. Johnson and C. G. Wilson, "A review of vagus nerve stimulation as a therapeutic intervention," (in eng), J Inflamm Res, vol. 11, pp. 203-213, 2018

3.   M. E. Downs, S. A. Lee, G. Yang, S. Kim, Q. Wang, and E. E. Konofagou, "Non-invasive peripheral nerve stimulation via focused ultrasound in vivo " Physics in Medicine and Biology, vol. 63, no. 3, p. 035011, 2018

4.  V. Pashaei, P. Dehghanzadeh, G. Enwia, M. Bayat, S. J. A. Majerus, and S. Mandal, "Flexible Body-Conformal Ultrasound Patches for Image-Guided Neuromodulation," IEEE Transactions on Biomedical Circuits and Systems, pp. 1-1, 2019,

5.   T. Costa, C. Shi, K. Tien, J. Elloian, F. A. Cardoso, and K. Shepard, "An Integrated 2D Ultrasound Phased Array Transmitter in CMOS with Pixel Pitch-Matched Beamforming," IEEE Transactions on Biomedical Circuits and Systems, vol. 15, no. 4, pp. 731-742, 2021



1st part:  Literature review of piezoelectric transducers and their manufacturing

2nd part: Design, fabrication and acoustic characterization of a uVNS device


MSc students from Microelectronics, Biomedical Engineering or Mechanical Engineering. Interested students should include their CV, the list of courses attended, and a motivation letter.


dr. Tiago Costa

Bioelectronics Group

Department of Microelectronics

Last modified: 2022-02-25