Reinventing digital touch with soft, air-driven actuators
Krishna Dheeraj Kommuri defended his PhD thesis at the Department of Mechanical Engineering on January 22.
Tactile perception, our ability to experience the world through touch, is increasingly makings its way into digital technology to create more natural and immersive experiences. Common examples include vibration alerts on phones and tactile feedback in gaming controllers, but it can also support advanced applications such as minimally invasive robotic surgery. However, much of the potential of haptics, the use of tactile perception in technology, remains unexplored because the field is complex and there is a limited availability of hardware capable of generating diverse and well-controlled tactile sensations. In his PhD research, Krishna Dheeraj Kommuri addresses these challenges by introducing the Pneumatic Unit Cell (PUC) actuator to enable research into tactile perception.
A tactile actuator system should deliver multiple forms of tactile stimuli, adapt to sensitivity differences across the body, function both as a single actuator and within an array, and allow flexible array configurations to support a variety of research needs. In addition, the system should be easy to fabricate and cost-effective to ensure accessibility for researchers. Based on these requirements, Krishna Dheeraj Kommuri presents the PUC actuator. This silicone-based, air-driven actuator can provide both static pressure and vibration, enabling a wider range of tactile sensations than many commercially available alternatives.
A tactile actuator system should deliver multiple forms of tactile stimuli, adapt to sensitivity differences across the body, function both as a single actuator and within an array, and allow flexible array configurations to support a variety of research needs. In addition, the system should be easy to fabricate and cost-effective to ensure accessibility for researchers. Based on these requirements, Krishna Dheeraj Kommuri presents the PUC actuator. This silicone-based, air-driven actuator can provide both static pressure and vibration, enabling a wider range of tactile sensations than many commercially available alternatives.
Results from psychophysical studies
To measure the range of stimulus strengths delivered by these actuators, psychophysical studies were conducted with participants. The results demonstrate the wide operational range of the PUC actuators. Further studies show that using multiple PUC actuators together can create richer and more complex surface features, including patterns that can be felt on the fingertip and sensations that seem to move smoothly along the forearm. Although each PUC actuator produces a single point of sensation, combining them allows the system to create larger and more continuous tactile experiences.
Simulating affective touch
Haptics also play a role in social and affective communication. Kommuri investigated the use of PUC actuators for this purpose by simulating a stroking stimulation along the forearm. A study testing this approach shows that such stimulation influences perceived pleasantness. This indicates that soft, air-driven actuators can evoke affective responses, which is valuable for applications involving emotional or social touch cues.
Overall, this research demonstrates the potential of PUC actuators in delivering tactile stimuli. It offers insights into their mechanical behavior and perceptual impact, laying the groundwork for future exploration into haptics using PUC actuators. The work also highlights the system鈥檚 potential for customizability through design. The findings and tools presented provide a foundation for researchers to further develop new forms of sensory interaction and communication.
Title of PhD thesis: . Supervisors: Dr. Irene Kuling, Prof. Henk Nijmeijer and Dr. Femke van Beek.