How it works

Interaction zones and form factors

1163 views 28/07/2018 Nicci 10

Ultrahaptics products allow you to experience and develop your own mid-air, touchless haptic applications. At the heart of Ultrahaptics is an array of ultrasonic transducers that are synchronised to create an acoustic field in front of the array. The focused energy in this zone creates the haptic feedback that you can feel. We call this the interaction zone. Its size and shape are dependent on the number of transducers and their positions.

The size of the interaction zone and complexity of haptic feedback increases with the number of transducers.

The interaction zone can be simulated to show the relative strength of sensation that can be felt. Here, we show simulated interaction zones for a selection of our products. The two-dimensional cross-sections indicated ranges for best haptic quality – bright green – out to orange for acceptable and red for edge cases. All dimensions are in centimetres.

STRATOS Inspire Haptic Module (USI)

256 transducer array, rectangular “sunflower” layout.

See the STRATOS Inspire integration guide for more details.

STRATOS Explore Development Kit (USX)

256 transducer array, 16×16 square

STRATOS Explore interaction zone

TOUCH Development Kit (UHDK5)

192 transducer array, 14×14 – 4 square

TOUCH interaction zone

You should avoid attempting to create haptics outside the interaction zone, as they may feel inconsistent or weak.

We want to integrate Ultrahaptics into our product. Can we change the layout?

Our development kits use flat, continuous arrays and are ideal for evaluating the technology or developing a proof-of-concept application. You may have reached the stage where you are considering integrating Ultrahaptics into your product but have specific space and layout requirements that do not fit with our existing products.

When it comes to deciding your layout and array placement, there is flexibility in the array design. Transducer placement and positioning can be customised for specific applications. Transducers can be split into groups, curved across a surface or pitched to optimise the interaction zone.

The number of transducers required will depend on the range in which sensation is to be effectively perceived. Also, consider the capabilities of your hand tracking camera device: this too will have an effective range.

Customer Case Study Example

We have carried out some analysis of interaction zone behaviour for a number of different transducer layouts: strips, frame-like, U-shape and a number of other, irregular shapes.

We found that short blocks of transducers performed better than elongated shapes. When testing strips, frames, and U-shaped arrays, we also noted that array blocks or individual transducers could be pitched to maximise control point strength.

NOTE: Any attempt to modify a development kit by dismantling, breaking apart, disabling or removing transducers will render your warranty void. The STRATOS Inspire haptic module is a fully integrated device and should not be opened.

In the example below, we have simulated a frame-shaped array. The transducers at the centre of the array have been disabled.

Focal point position

Note: Individual transducers cannot be disabled with our current API. However, you can simulate this by covering transducers with a non-porous material, such as card or plastic.

The interaction zone is enlarged by applying the slight pitching in the second interaction zone diagram.

Interaction zone reference plane

Ultrahaptics is happy to discuss the best ways to integrate our product into your product. We can simulate and help optimise your array design with our bespoke, engineering services.

To discuss your specific requirements please contact us.

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