You’re Touching on Something Here

Since virtual reality relies primarily on visual and auditory stimuli, it is incapable of providing the same type of sensory feedback as real-world interactions. The inability to feel objects and textures in virtual worlds can lead to a disconnect between the user and the simulated environment. This lack of tactile feedback can also make it difficult to interact with virtual objects in a realistic way. This limitation of current technologies is preventing more widespread adoption of virtual reality in fields like education, healthcare, retail, robotics, and manufacturing. One area that has been explored recently to help fill this gap between real and virtual worlds is telehaptics.

Telehaptic devices are an emerging type of technology that allow users to interact with and experience virtual objects through the sense of touch. Through haptic feedback, users can experience a tactile sensation that is triggered by their interaction with virtual objects, making it possible to feel the texture and shape of a virtual object as if it was actually being touched. These devices hold lots of promise, but as they are currently implemented, telehaptic devices are bulky and have low resolution actuators. This lack of sufficient resolution prevents the reproduction of sophisticated tactile sensations.

A recent breakthrough in the field has been reported by a team of researchers at the Electronics and Telecommunications Research Institute in South Korea. They have developed an ultrathin, flexible tactile interface with high resolution that is designed to adhere to the skin. Both sensors and actuators are incorporated into the substrate to record and generate pressures in a wide frequency range. Various types of stimuli, including those produced by shapes, textures, and vibration patterns can be simulated by the device. Latency in communicating with external devices is very low, on the order of 1.5 milliseconds, which helps to keep the illusion alive.

The skin patch is a small fraction of the width of a human hair in thickness and has a checkerboard pattern of sub-millimeter scale piezoceramic actuators and sensors woven into it. The actuators are spaced at 1.8 millimeter intervals to provide a high resolution tactile interface. Initially, the team used their methods to create a skin patch for the fingertip. The characteristics of the design allow that patch to reproduce the sensation of touching materials like cotton, polyester, and spandex. It can also simulate the feeling of touching three-dimensional objects. To achieve such accurate reproductions of sensations, measurements are first captured from the onboard sensors while interacting with an object. This information is then used to activate the actuators in a way that simulates that interaction.

Moving forward, the team plans to enhance their telehaptic system by enhancing the performance and form factor of the piezoelectric actuator such that many more types of tactile stimuli, beyond vibration, can be generated. They are also exploring ways to integrate more types of sensors and actuators into the design, so that additional sensations, like heat and coldness, can be experienced by a wearer of the device. As the researchers continue to build upon their work, the device should become more capable of producing immersive virtual experiences.