3D Tactile Feedback via Ultrasonic Phased Array Focusing

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Solution Overview

Problem

Current tactile feedback systems are limited in their ability to provide three-dimensional tactile feedback using acoustic radiation pressure, failing to effectively simulate the sensation of three-dimensional objects in free space.

Innovation Solution

A three-dimensional tactile feedback device comprising a two-dimensional array of ultrasonic transducers and a control system that continuously switches discrete points of tactile feedback at a frequency perceivable by humans, such as 1 KHz, to produce tactile stimulation of three-dimensional objects in free space, utilizing the Phased Array Focusing technique to generate perceivable radiation pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a two-dimensional array of ultrasonic transducers is used to generate acoustic radiation pressure, then three-dimensional tactile feedback can be produced, but the system complexity increases

Engineering Contradiction:

Improvethree-dimensional tactile feedback capabilityVSAvoidtransducer array complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system divides the three-dimensional tactile feedback task into multiple discrete focal points that can be independently controlled. Each point in the 3D space can be addressed by specific subsets of transducers in the array, allowing complex 3D objects to be constructed from simpler point-wise acoustic radiation pressure applications.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extends traditional two-dimensional tactile display technology into three-dimensional space by utilizing the z-axis (depth) dimension. By controlling the phase and amplitude of ultrasonic waves from the 2D transducer array, the system creates focal points at various depths, enabling true 3D tactile feedback without physical contact.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If discrete points of tactile feedback are continuously switched at high frequency, then realistic three-dimensional object perception is achieved, but energy consumption increases

Engineering Contradiction:

Improvetactile feedback realismVSAvoidtransducer switching energy

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system employs periodic switching of discrete tactile feedback points at frequencies above the human perception threshold (typically >200 Hz). This periodic activation creates the illusion of continuous 3D object presence while actually energizing only specific transducer subsets at intervals, reducing overall energy consumption compared to continuous full-array operation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

Rather than activating all transducers simultaneously, the system uses partial action by engaging only the necessary subset of transducers required to create the current focal point. This selective activation minimizes energy consumption while maintaining the perception of complete 3D object coverage through rapid sequential updating.

Inventive Principle:

Principle #16Partial or excessive action

3Ease of operation

If acoustic radiation pressure is used for non-contact tactile display, then user comfort is improved, but the force magnitude is limited

Engineering Contradiction:

Improvenon-contact interaction comfortVSAvoidacoustic radiation force

Core Design Contradiction:

Ease of operationVSForce

Solution Approach 1:

The system optimizes the acoustic radiation force by adjusting key parameters including ultrasonic frequency, amplitude, and focal point concentration. By changing these parameters, the system maximizes the radiation pressure effect within safety limits, enhancing the perceptible force without compromising the non-contact comfort advantage.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enables the creation of high-resolution three-dimensional tactile experiences without physical contact, providing a realistic and intuitive way to interact with virtual objects by generating acoustic radiation forces at focal points, allowing users to perceive complex 3D shapes and objects.

Implementation Method 1

Ultrasonic noncontact tactile display is based on the phenomenon of acoustic radiation pressure. When the focused ultrasound beam is reflected by the surface of an object, the surface is subjected to a constant force in the direction of the incident beam.

Methodology Applied

Scientific EffectAcoustic radiation pressure: Acoustic Radiation Pressure

Implementation Method 2

Methodology Applied

Scientific EffectPhased array focusing: Focusing

Data Source

PatentUS10133353B2Three dimensional tactile feedback system

Publication Date: 2018.11.20 NEW YORK UNIV IN ABU DHABI CORP

AI summary

A three dimensional tactile feedback includes a two dimensional array of ultrasonic transducers and a control device configured to control the ultrasonic transducers. The ultrasonic transducers re configured to project discrete points of tactile feedback in three dimensional space. The tactile feedback system is configured to continuously switch the discrete points of tactile feedback at a frequency at which a human is capable of perceiving tactile stimulation in order to produce tactile stimulation of a three dimensional object in free space.