A Wearable Ultrasonic Neurostimulator-Part II: A 2D CMUT Phased Array System With a Flip-Chip Bonded ASIC.

A 2D ultrasonic array is the ultimate form of a focused ultrasonic system, which enables electronically focusing beams in a 3D space. A 2D array is also a versatile tool for various applications such as 3D imaging, high-intensity focused ultrasound, particle manipulation, and pattern generation. However, building a 2D system involves complicated technologies: fabricating a 2D transducer array, developing a pitch-matched ASIC, and interconnecting the transducer and the ASIC.

A Wearable Ultrasonic Neurostimulator - Part I: A 1D CMUT Phased Array System for Chronic Implantation in Small Animals.

In this work, we present a wireless ultrasonic neurostimulator, aiming at a truly wearable device for brain stimulation in small behaving animals. A 1D 5-MHz capacitive micromachined ultrasonic transducer (CMUT) array is adopted to implement a head-mounted stimulation device. A companion ASIC with integrated 16-channel high-voltage (60-V) pulsers was designed to drive the 16-element CMUT array.

A Sub-Millimeter Lateral Resolution Ultrasonic Beamforming System for Brain Stimulation in Behaving Animals.

In this paper, we present a second-generation wireless ultrasonic beamforming system, aiming for a truly wearable device for brain stimulation in small behaving animals. The fully-integrated, battery-operated system enables a self- contained untethered system. The system is partitioned into two parts for weight distribution: (1) a 1D capacitive micromachined transducer (CMUT) array on a separate head-mountable flexible printed circuit board (PCB), (2) a rigid back-mountable PCB including electronics such as a custom ASIC, a power management unit, a wireless module, and a battery.

Towards an Untethered Ultrasound Beamforming System for Brain Stimulation in Behaving Animals.

In this paper, we present a wireless ultrasound transmit (TX) beamforming system, potentially enabling wearable brain stimulation for small awake/behaving animals. The system is comprised of a 16-element capacitive micromachined transducer (CMUT) array, driven by a custom phased-array integrated circuit (IC), which is capable of generating high-voltage (13.5 V) excitation signals with sixteen phase delays and four amplitude levels.