1

Haptics in Touch Screens

Anish Hegde4NM09EC143

2

Contents

1 Haptics in Touch Screens 1.1 Introduction1.2 Restoration of Mechanical feel

2 Actuator Based Haptics 2.1 Actuators 2.2 Designing a Haptic System 2.3 Disadvantages3 Electrostatic Force Based Haptics

3.1 Introduction 3.2 Working

3.3 Advantages over conventional Haptics4 Tactus Tactile Display 4.1 Introduction 4.2 Working 4.3 Advantages5 Conclusion6 References

3

1.1 Introduction

• Haptics or Haptic Technology is derived from the Greek word Haptikos meaning “to contact” or “to touch”.

• Haptics are found in many of the consumer devices that are used every day.

• The rumble effect in the console game controller and the reassuring touch vibration one receive on ones smartphone dial pad are both examples of haptic effects.

• In the world of mobile devices, computers, consumer electronics, and digital devices and controls, meaningful haptic information is frequently limited or missing.

• For example, when dialling a number or entering text on a conventional touchscreen without haptics, users have no sense of whether they’ve successfully completed a task.

4

Improved Usability

• By restoring the sense of touch to otherwise flat, cold surfaces, haptics creates fulfilling multi-modal experiences that improve usability by engaging touch, sight and sound.

• From the confidence a user receives through touch confirmation when selecting a virtual button to the contextual awareness they receive through haptics in a first person shooter game, haptics improves usability by more fully engaging the user’s senses.

5

Enhanced Realism

• Haptics injects a sense of realism into user experiences by exciting the senses and allowing the user to feel the action and nuance of the application.

• This is particularly relevant in applications like games or simulation that rely on only visual and audio inputs.

• The inclusion of tactile feedback provides additional context that translates into a sense of realism for the user.

6

1.2 Restoration of Mechanical Feel

• Today’s touchscreen-driven devices lack the physical feedback that humans frequently need to fully understand the context of their interactions.

• By providing users with intuitive and unmistakable tactile confirmation, haptics can create a more confident user experience and can also improve safety by overcoming distractions.

• This is especially important when audio or visual confirmation is insufficient, such as industrial applications, or applications that involve distractions, such as automotive navigation.

7

So How Do We Go About Doing That ?

8

The three technologies we will be discussing:

1.Actuator Based Haptics

2.Electrostatic Force Based Haptics

3.Tactus Tactile Based Haptics

9

2. Actuator Based Haptics

• This the most primitive form of haptics and has come a long way.

• It initially begun with game consoles and graduated into bar mobile phones.

• But most recently a company named Immersion Technologies has revolutionised this form to give enhanced user experience and a way to touch things on a 2D screen.

10

2.1 Actuators

• In engineering, actuators are a subdivision of transducers. They are devices which transform an input signal (mainly an electrical signal) into motion.

• Motors are mostly used when circular motions are needed, but can also be used for linear applications by transforming circular to linear motion with a bolt and screw transducer. On the other hand, some actuators are intrinsically linear, such as piezoelectric actuators.

Motor Actuator Piezo Electric Actuator

11

12

2.2 Designing a Haptic System

A haptic system must integrate the following components:

• Actuator − In hand-held devices, the actuator is typically mounted in a corner of the device casing to maximize the vibrations felt by the hand holding the device.

• Electronics − A haptic system in a hand-held device will use a power amplifier to drive the actuator. The power amplifier takes device battery voltage (or a regulated 3V) as the power source. A control signal input modulates the voltage applied across the actuator for a designated time period.

13

(Cont..)

• Control Software − This is the brains of a haptic system and it should be fine-tuned to the capabilities of the system’s actuator. The controller takes an abstract instruction from a software application and runs a control algorithm that will continually adjust the voltage applied across the actuator to create the desired sensation.

• Application Software − This is the software application that is visible to the device user. It coordinates the playback of touch effects according to prescribed user-interface events. Haptic behaviour can be implemented at the application or OS level.

14

15

Disadvantages

• Consumes a lot of power .

• The major disadvantage of an actuator based Haptic model is that it also packs in some noise .

• Sometimes additional vibrations can also get a little bit uncomfortable.

16

3. Electrostatic Force Based Haptics 3.1 Introduction

• A standard touchscreen employs what is called capacitive sensing to respond to a user's prods.

• The electric charge held by a capacitor can be affected by a nearby conductor.

• Since fingers are conductive, they have this effect.

• An array of capacitors underneath the transparent cover of a touchscreen can thus locate an approaching digit, causing the device's software to react accordingly.

17

3.2 Working• Senseg's “feelscreens” reverse this process. • By applying a proprietary coating to the screen and varying the

electrical charge in it, that screen can be made to attract or repel the flesh of a touching finger.

• The electrostatic force involved is small, but it is enough for the nerve-endings in a fingertip to detect.

• Modulate the force appropriately and you can induce a feeling of sandpaper, corrugated iron or fabric.

18

• Senseg patented solution creates a sophisticated sensation of touch using Coloumb’s force, the principle of attraction between electrical charges.

• By passing an ultra-low electrical current into the insulated electrode, Senseg’s Tixel, the proprietary charge driver can create a small attractive force to finger skin.

• By modulating this attractive force a variety of sensations can be generated, from textured surfaces and edges to vibrations and more.

19

The Senseg Tixel

• The Tixel is the means by which Senseg’s technology transmits electro-tactile stimulus.

• It is an ultra-thin durable coating on the touch interface that outputs tactile effects.

• Senseg’s patented Tixel can be applied to almost any surface, flat or curved, hard or soft, transparent or opaque.

• Because there are no moving parts in Senseg’s solution it can scale to almost any size of device.

• Moreover, with no mechanical inertia Senseg tactile response is immediate .

20

3.3 Advantages over Conventional Haptics

• Unlike effects created by mechanical vibration and piezo solutions, Senseg is silent.

• With Senseg application developers have precise control of the location and type of effect users experience.

• Senseg technology scales from touch pads, smart phones and tablets to the largest touch screens without increasing manufacturing complexity.

21

22

4. Tactus Tactile Display

4.1 Introduction

• The Tactus Tactile Layer panel provides a next-generation user interface with real physical buttons, guidelines, or shapes that rise out of the surface of a touchscreen on demand.

• The Tactile Layer component is a completely flat, transparent, dynamic layer that sits on top of the touch sensor and display.

• When triggered, this thin layer deforms and buttons or shapes of a specific height, size and firmness appear on the surface.

• Users can feel, press down and use these physical buttons just like they would use keys on a keyboard.

• When they are no longer needed, the buttons recede into the surface and become invisible.

23

24

3.2 Working

• Made of a thin multi-layer stack, the top-most layer consists of an optically clear polymer.

• A number of micro-holes connect the top layers of the panel to a series of micro-channels that run through the underlying substrate.

• The micro channels are filled with a fluid whose optical index of refraction matches that of the surrounding material, making it fully and evenly transparent when light from the display passes through.

25

• Increasing the fluid pressure causes the fluid to push up through the holes and against the top polymer layer, making it expand in pre-defined locations.

• This enables an array of physical and completely transparent buttons to rise out of the surface.

• A small internal controller that interfaces with the processor of the touchscreen device controls the rise and fall of the buttons.

• The controller allows a proximity sensor or a software application to control the state of the buttons.

26

27

4.3 Advantages

• Power requirements of the Tactile Controller used to actuate the panel are minimal.

• The system only consumes a small amount of power to raise or lower the buttons. Once the buttons are raised, they remain enabled for as long as they are needed – be it a few seconds or several hours – without any additional power consumption.

• This is possible because the pressure used to raise the buttons remains present, causing the buttons to automatically pop back up each time they are pushed.

28

Upcoming Products

Apple's take on haptic technology places piezoelectric actuators under the display, which allows for localized feedback when touched. Because the sensation is localized (as opposed to vibrating the whole device as other haptic solutions do) users would be able to feel individual buttons and understand their relative positions on the display.To allow the haptic layer to sense not only placement, but pressure as well, the display would have to have some minimal flexibility.

The combination of haptic feedback and force-sensing actuators could allow Apple to produce a completely new set of touch-screen gestures to include in iOS devices.

29

CONCLUSION

Touch was one of our first sense of feeling and probably the last one . It plays a huge role in the way we perceive our surroundings and also how we interact with them. Haptics and Haptic based technologies have come a long way in bringing this technology into reality. Soon Consumer electronics will come packing with features mentioned in the report. Apple Inc. has filed several patents on Haptics related technology. We would be able to see devices with this technology soon enough.

The drive in Consumer Electronics has always been to integrate the vast differences between the virtual and the physical world. This technology brings us one step closer to realising it.

30

REFERENCES [1] “Tools to Assist in the Design and Implementation of Haptic Effects”, [Online]. Available http://www.immersion.com/resources/designing-haptics-system/index.html [Accessed: November 2012][2] “Haptics is Quite Literally The Science of Touch”, [Online]. Available:http://www.immersion.com/haptics-technology/what-is-haptics/index.html [Accessed: November 2012][3] “Haptics-in-Touchscreen-Hand-Held-Devices” ,Immersion Corporation, April 2012[4] “Senseg Is Haptics Re-Imagined and Realized”, [Online]. Available: http://senseg.com/technology/senseg-technology [Accessed: November 2012][5] “Tactus_Technology_White_Paper”, Tactus Corporation , December 2011[6] “Haptics :Reinventing the finger”, [Online] Available : http://www.economist.com/blogs/babbage/2012/06/haptics .[Accessed : November 2012][7] “Appearing and Disappearing haptic User Interface has first public demonstration”. [Online]. Available : http://www.tactustechnology.com/release_120605.html [Accessed : November 2012][8] “Electrostatic Induction”, Corollary Theorems . [Online ] Available : ttp://www.corollarytheorems.com/Design/VIZ.htm [Accessed November 2012]