Concept and Principle
Natural communication by haptic interaction
We humans rely not only on visual and auditory information but also on haptic interactions, especially in intimate human communication. Recent technologies have led to the development of amazing handheld devices for visual and auditory communication, but most mobile haptic devices seem to be limited to producing simple vibrations for alerts and attention. To realize rich haptic communication with mobile devices, we may need to overcome the limitations of “physics” by deeply investigating human sensation and perception.
Illusions: a peep into human sensory perception
Information from the external world comes into the brain through various sensory organs, but detected sensory signals do not directly represent the external world. Various signals, each carrying “a piece of an external event”, are selected and integrated in the brain to form coherent representations of external events in our perception. Interestingly, because of the nature of sensory detection and processing in the brain, an external event is sometimes misrepresented in our perception, which is called an illusion. Illusions therefore provide important cues for understanding the mechanisms of human sensation and perception.
Asymmetric oscillation producing being-pulled sensation
Buru-Navi exploits the nonlinearity of human haptic perception to induce force sensation. When a small mass in the Buru-Navi device oscillates along a single axis with asymmetric acceleration, a person holding this device typically experiences a kinesthetic illusion characterized by the sensation of being continuously pulled (or pushed) by the device. Although temporal averages of the two opposing forces (a strong and short force in one direction and a weak and long one in the other direction) applied alternately are the same, the holder feels an illusory sensation of being pulled in one direction.
Innovative gadget inspired by brain science
In addition to such human perception characteristics revealed in our research group, we have found that a key point for miniaturizing a haptic gadget, as we’ve done with Buru-Navi 3, is the stimulus optimization for human tactile sensation. Down-sizing a mobile haptic device is not easy because the physical intensity of the vibration decreases with decreasing device size. To overcome this problem, we have focused on the finger tips, under which tactile receptors are densely distributed. With the highly sensitive capacity of receiving rich information from these receptors, the brain can capture the details of tactile interactions with a weak stimulus. Additionally, by carefully designing the pattern of vibration for the tangential motion sensation, we have succeeded in producing a strong sensation of being pulled.
For tugging at your hand and heartstrings
Tactile interactions by means of touching, patting, stroking, pulling, pushing, hitting, and guiding frequently appear in fundamental and intimate relationships in humans and in animals. We therefore believe that tactile sensation is closely connected to emotional and deep communication. We will continue to develop new ‘force display gadgets’ that can strongly tug at your hand and your heartstrings for future telecommunication.
- MIT Technology Review (2014/7/21) - Could "Force Illusions" Help Wearables Catch On?
- AIP Publishing (2014/7/22) - News Picks: New handheld devices provide haptic feedback
- Mashable (2014/7/22) - Haptic Feedback Could Give Wearables a Push (or Pull)
- ACM TechNews (2014/7/23) - Could 'Force Illusions' Help Wearables Catch On?
- EE Times India (2014/7/23) - Force illusions seen to drive wearables adoption
- Wearable.ai (2014/7/23) - Wearables Could Benefit From Haptic Feedback
- Wearable.co.uk (2014/7/24) - Wearables of the future could push us around
- Wearable Tech World (2014/7/24) - Force Illusions Offer a New Means to Interact With Wearables
- ETCentric (2014/7/25) - SIGGRAPH: Haptic Interfaces to Pull and Push Wearable Users
- Eye on the Future (2014/7/25) - Japanese Researchers Demonstrate "Force Illusions"