About AUTD3

AUTD3 is an ultrasound phased array device for midair haptics. An ultrasound phased array is an array of ultrasound transducers whose phases can be individually controlled (typically arranged in a grid). By controlling the phase of the ultrasound, it is possible to generate arbitrary sound fields in space.

The energy of sound waves sufficiently focused using a phased array generates acoustic radiation pressure. This pressure can be used to push the surface of the human body without contact. The position of the focal point can be freely controlled by electronically controlling the phased array. Additionally, by solving the inverse problem, it is possible to create more complex sound pressure spatial distributions, not just a single focal point.

The upper limit of the pressure that can be generated by a phased array is currently about $50mN/c{\mathrm{m}}^2\sim 5gf/c{\mathrm{m}}^2$. The spatial resolution is up to the wavelength used (about $\sim 8.5\mathrm{mm}$ at $40\mathrm{kHz}$). Although there are such limitations with phased arrays, it is attracting attention as a technology that can freely design the spatiotemporal distribution of force and create various haptic sensations.

This field of technology, which stimulates haptics without contact, is called Midair Haptics, and we call this ultrasound midair haptic device Airborne Ultrasound Tactile Display (AUTD). The essential part of AUTD was proposed and established by the University of Tokyo from 2008¹ to the early 2010s². Since then, universities and companies around the world have entered the field, and active research and development are being conducted. AUTD3 is the third version of AUTD developed by our Shinoda-Makino Laboratory at the University of Tokyo.

A list of research using AUTD is posted on the laboratory’s homepage. Please refer to it as well.

This manual summarizes the autd3 software library for operating this AUTD3.