Optimisation of ultrasound sensors for enhanced haptics

Haptic technology has seen significant development in recent years, enabling technology to better stimulate our sense of touch. Ultrasound haptic devices are one example. These use arrays of transducers to focus ultrasound beams, controlling their dynamic properties to create localised pressures that stimulate skin in mid-air, thereby delivering haptic experiences for a range of applications, including public displays and mixed reality. However, we are reaching the limits of what can be achieved with our current understanding of ultrasonic transducers. The major goal of this project is to investigate how these transducer limitations can be overcome, to deliver more responsive and higher quality haptic feedback.
This project proposes a step change in how we implement ultrasound sensors in haptic devices. We tend to look at this problem by developing systems with algorithms to accommodate standard / conventional configurations of ultrasound sensor. However, we think this problem can be tackled the other way round, by optimising and engineering the dynamics of the sensor to integrate with algorithms, thus building an immersive haptic experience. One proposed route to achieving this is via advanced, adaptive materials such as shape memory alloys or metamaterials, enabling dynamic properties including resonance and beam shape to be controlled, presenting an exciting, as yet unexplored, opportunity.
This project will be supported by the School of Computing Science at the University of Glasgow, whom already have experience in engineering human-computer interfaces for ultrasound haptic technologies. Whilst significant progress has been made in human-computer interaction, optimised configurations of sensor constitute a clear opportunity to build on the capacity of existing systems. This project will therefore deliver the missing expertise in how ultrasonic sensors can be integrated into advanced communication technologies. Specifically, we do not yet fully understand the relationship between the physical characteristics of ultrasonic sensors, and their dynamic performance in a haptic environment. This research forms the bridge between ultrasound sensors, mathematical techniques, and the interface of human-computer interaction, whilst at the same time strengthening current industry relationships with Ultraleap, a leading global organisation in haptic technologies, and CeramTec UK, leaders in piezoelectric and active materials.

Key Objectives

Haptic technologies have grown in popularity with advances in virtual reality and mobile phones, now able to accommodate basic remote sensing and activation. Recently, a consequence of COVID-19 has renewed the drive towards touchless technologies, in addition to those desired for inspection technologies in hazardous or hostile environments (for example radioactive or high temperature for humans). Haptics is postulated as a viable route for such capabilities. To achieve this, we need significantly greater understanding of how the characteristics of ultrasound waves in air can be engineered to deliver the required haptic experience. To tackle this ambitious challenge, the following general set of objectives is proposed:

1. Methodically assess the limitations associated with the current range of ultrasound sensors used in haptic systems, through a combination of mathematical modelling and experimental analysis.
2. Determine optimal sensor configurations to improve dynamic performance.
3. Develop a strategy to fabricate a novel prototype sensor for ultrasound haptics, using metamaterials, advanced materials, or otherwise.
4. Engineer an interface for a sensor, or sensor array, to be implemented in a suitable ultrasound haptic system for industrial trials.