WIRELESS HIGH-SPATIAL-RESOLUTION NEUROMODULATION VIA ULTRASOUND-DRIVEN CMUT MICROTRANSDUCERS

Ultrasound (US) neuromodulation has emerged as a non-invasive, wireless method to modulate neural activity without invasive procedures. Using transcranial ultrasound stimulation (tUS), mechanical energy is transmitted through the skull to access superficial and deep brain structures. Although penetration without implants is valuable, current US neuromodulation is limited in spatial resolution due to diffraction, skull aberration, and the large focal volumes of low-frequency transducers, often spanning millimetres to centimetres. These constraints limit precise targeting of discrete neural populations and complicate causal links between stimulation and behavior¹.

To overcome this limitation, we propose integrating capacitive micromachined ultrasonic transducers (CMUTs) as local actuators driven by externally applied US fields. CMUTs, fabricated at sub-millimetre scales, function as microscopic receivers/transducers that convert incident ultrasound into localized mechanical or electrical forces, enabling stimulation with spatial precision orders of magnitude finer than free-field US².

Here, we delineate operational regimes of US parameters that elicit or do not elicit direct neural modulation, establishing thresholds for ultrasonic brain stimulation. Defining these thresholds allows US to function exclusively as a wireless power delivery mechanism for CMUT activation. By combining the non-invasive propagation of US with implanted CMUT actuators, we aim to wireless, high-spatial-resolution neuromodulation, bridging the gap between non-invasive techniques and fine-scale control required for basic neuroscience and therapeutic applications.

1Martin et al. Nature communications 16.1 (2025): 8024.

2Lee et al. Microsystems & Nanoengineering 5.1 (2019): 28.

Funded by the EUROPEAN INNOVATION COUNCIL AND EISMEA - European Union.

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