About AUTD3

AUTD3 is an airborne ultrasound phased array device for midair haptics. A phased array is an array of ultrasound transducers that can control the phase of each transducer individually. By controlling the phase of the ultrasound, an arbitrary sound field can be generated in space.

The energy of sound waves that are well focused using a phased array produces acoustic radiation pressure. This pressure can be used to press the surface of the human body without any contact. The position of the focused focal point can be freely controlled by electronically controlling the phased array. Moreover, by solving the inverse problem, not only a single focal point but also a more complicated spatial distribution of sound pressure can be created.

The upper limit of the magnitude of pressure that can be generated by the phased array is currently about $50mN/c{\mathrm{m}}^2\sim 5gf/c{\mathrm{m}}^2$. Also, the spatial resolution is limited to about the wavelength (for example, about $8.5\mathrm{mm}$ for $40\mathrm{kHz}$). Despite these limitations, phased arrays have attracted attention as a technology that allows us to freely design the spatio-temporal distribution of force and create various tactile sensations.

We call this field of non-contact tactile stimulation technology Midair Haptics, and we call this phased array device Airborne Ultrasound Tactile Display (AUTD). The essential part of AUTD was proposed and established by the University of Tokyo between 2008¹ and the early 2010s². Since then, universities and companies from various countries have entered into this field, and active research and development has been conducted. AUTD3 is the third version of AUTD developed in Shinoda-Makino Laboratory of the University of Tokyo.

A list of research using AUTD can be found at our laboratory's homepage. Please also refer to this page.

This manual describes the autd3 software library for operating AUTD3.