Noncontact Tactile Display Based on Radiation Pressure of Airborne Ultrasound

TLDR

Acoustic radiation pressure, a nonlinear ultrasound phenomenon, underlies the tactile display. The paper presents a contact‑free tactile display that delivers unrestricted tactile feedback in air. The system employs 324 individually phased and intensity‑controlled ultrasound transducers to create a 3‑D stress field and a focal point. The prototype achieves a 16 mN focal force with a 20 mm diameter, produces vibrations up to 1 kHz, and supports an interaction system that lets users see and touch virtual objects.

Abstract

This paper describes a tactile display which provides unrestricted tactile feedback in air without any mechanical contact. It controls ultrasound and produces a stress field in a 3D space. The principle is based on a nonlinear phenomenon of ultrasound: Acoustic radiation pressure. The fabricated prototype consists of 324 airborne ultrasound transducers, and the phase and intensity of each transducer are controlled individually to generate a focal point. The DC output force at the focal point is 16 mN and the diameter of the focal point is 20 mm. The prototype produces vibrations up to 1 kHz. An interaction system including the prototype is also introduced, which enables users to see and touch virtual objects.