Swiss researchers have developed a haptic glove that weighs just eight grams and can mimic the sensation of touching and grasping objects.
Known as DextrES, the device was designed and built by engineers at École polytechnique fédérale de Lausanne (EPFL) and ETH Zurich. With a thickness of just 2mm, the nylon glove compares favourably to existing haptic devices that are bulky and unwieldy. It is capable of generating up to 40 Newtons of holding force on each finger with just 200 Volts and only a few milliWatts of power. Although currently powered from mains supply, it also has the potential to run off a small battery, providing even more flexibility.
“We wanted to develop a lightweight device that – unlike existing virtual-reality gloves – doesn’t require a bulky exoskeleton, pumps or very thick cables,” said Herbert Shea, head of EPFL’s Soft Transducers Laboratory (LMTS). “The system’s low power requirement is due to the fact that it doesn’t create a movement, but blocks one.”
DextrES has thin pliable metal strips running over the fingers, with the strips separated by a thin insulator. When the user’s fingers come into contact with a virtual object, the controller applies a voltage difference between the metal strips, causing them to stick together via electrostatic attraction. This produces a braking force that blocks movement of the digits, giving the same sensation as holding or grabbing an object. Once the voltage is removed, the metal strips glide smoothly and the user can once again move fingers freely.
“The human sensory system is highly developed and highly complex,” said Otmar Hilliges, head of the Advanced Interactive Technologies Lab at ETH Zurich.
“We have many different kinds of receptors at a very high density in the joints of our fingers and embedded in the skin. As a result, rendering realistic feedback when interacting with virtual objects is a very demanding problem and is currently unsolved. Our work goes one step in this direction, focusing particularly on kinesthetic feedback.”
According to the researchers, the next phase of the work will be to scale up the device and apply it to other parts of the body using conductive fabric, as well as explore the various applications for the haptic glove technology.
“Gamers are currently the biggest market,” said Shea. “But there are many other potential applications – especially in healthcare, such as for training surgeons. The technology could also be applied in augmented reality.”