Tribology of Touch for Haptic Perception

Surface Haptics

Surface haptics is an important branch in the growing haptic industry. The finger-device interface is crucial for the design and optimization of surface haptic devices. Our research aims to understand the tribology and Micro/Nano scale mechanics to design novel surface textures that have minimal sensitivity to environment and user variations.

  • To study the fingertip-substrate interaction, we designed and developed a custom tribometer. The tribometer is designed to measure the friction force between human fingertip and different surfaces (including electroadhesion enabled surfaces). A special normal force adjustment mechanism is developed to better control the normal force during the measurement of friction.We utilized an environmental chamber in the tribometer's design and development which enables us to measure and analyze friction force between the finger and different textured surfaces under different relative humidities.

Custom tribometer

  • Fingertip topography is copied with a dental mold and measured with white light interferometry. The power spectrum of these textures at different scales is measured and compared. Real-time contact area measurement will be performed with a fluorescent technique at super-resolution. 

  • To study the capillary formation and distribution in the finger-device interface we developed an algorithm to simulate the randomly distributed capillary in the interface

  • Considering the capillary effect in the finger-device interface, We also are interested in finger sweating behavior under different conditions

Sweat gland in action !!!

200 Micron