Download why we need haptics in touch screens?

HAPTICS IN TOUCH SCREENS
Heikki Säily
CONTENT
● Why we need haptics in touch screens
● Somatosensory system
● Vibrotactile feedback
● Electrotactile feedback
● Summary
WHY WE NEED HAPTICS IN TOUCH
SCREENS?
● To provide new dimensions of usage in touch
screen devices
● It can improve Human-Computer interaction
● Visually impaired
● To improve sales of product
● etc.
SOMATOSENSORY SYSTEM
● Can be separated to tactile and kinesthetic sense
● Technology used is usually focused on pressure
and vibration
SOMATOSENSORY SYSTEM:
PRESSURE AND VIBRATION
VIBROTACTILE FEEDBACK
● Lots of different types of actuators
○ Eccentric Rotating Mass motor, or ERM
○ Piezoelectric actuator, or "piezo"
○ etc.
VIBROTACTILE FEEDBACK:
ERM
● Direct current motor with an offset mass
attached to the shaft
VIBROTACTILE FEEDBACK:
ERM
● One of the most cost-effective actuator
● Vibration frequencies within 90-200hz range
● Excellent durability
● Slow
does not suit well for touch sensations
VIBROTACTILE FEEDBACK:
PIEZOELECTRIC ACTUATOR
● Bend when voltage is applied
● When voltage is decreased, returns back to
original state
VIBROTACTILE FEEDBACK:
PIEZOELECTRIC ACTUATOR
● Available in many different shapes, sizes,
thicknesses, voltage ranges ...
● Possible to use multiple piezo actuators to
provide stronger / localized haptic feedback
● Can be also used as sensors to detect vibration
or pressure
● Can provide fast and short (duration 2ms)
feedback
● Suitable for touch sensations
● Vibrate range from 150hz to 300hz
● Video
VIBROTACTILE FEEDBACK:
IMMERSION
● TouchSense
ELECTROTACTILE FEEDBACK:
SENSEG
● Finnish company
● Uses Coloumb's force (attraction between
electrical charges)
● Tixels (Tactile pixels)
ELECTROTACTILE FEEDBACK
●
●
●
●
●
●
Can be generated in different ways
Fairly new technology in touch screens
Silent
Can be integrated to displays of any shape
Transparent
Output and input
SUMMARY
● Receptors together create sensations
● Piezoelectric actuators seem to be widely
used and one can find good studies of them
● Electrotactile feedback technology is fairly
new, but has great potential
● Both have their own pros and cons