Technology of Touchscreen

Capacitive Touch Screen Technology

Capacitive touch screen technology is a popular and durable technology that is used in a wide range of applications. It has a higher clarity than resistive technology, but it only responds to finger contact and will not work with a gloved hand or pen stylus. A capacitive touch screen consists of a glass panel with a capacitive (charge storing) material coating its surface. Circuits located at corners of the screen measure the capacitance of a person touching the overlay.

Technology of Touchscreen 1Capacitive touch screen technology is often recommended to customers who would like the confidence of a brand name LCD such as NEC, which the capacitive touch screen would then be retrofitted to.

Limitations of capacitive touch screen technology:

  • Can not be used with a gloved hand
  • Can not be used with stylus
  • Requires periodic recalibration
  • Often retrofitted to standard non-touch LCD monitors which may not be as stable when touched
  • Not usually fitted to monitors when applications require dust, water, scratch or impact resistance

Popular Brands that often use capacitive touch screen technology:

  • 3M Microtouch

Resistive Touch Screen Technology

Resistive touch screen technology consists of a glass or acrylic panel that is coated with electrically conductive and resistive layers. The thin layers are separated by invisible separator dots. When operating, an electrical current moves through the screen. When pressure is applied to the screen the layers are pressed together, causing a change in the electrical current and a touch is registered.

Technology of Touchscreen 2Although clarity is less than with other touch screen types, resistive screens can be highly accurate and have the advantage of being pressure sensitive so it responds to any input device, including finger, gloved hand, or pen stylus

Resistive touch screen technology is the most cost effective technology on the market today. It is recommended when budgets do not allow more robust solutions.

Limitations of resistive touch screen technology:

  • Can be relatively easily damaged by scratching
  • Can be relatively easily damaged by poking
  • Can be relatively easily damaged by impact
  • Not recommended for public access applications
  • Requires periodic recalibration
  • Can wear through regular use over time

Popular Brands that often use resistive touch screen technology:

  • LG
  • TSS

SAW Touch Screen Technology

Technology of Touchscreen 3Surface Acoustic Wave (SAW) touch screen technology is based on sending acoustic waves across a clear glass panel with a series of transducers and reflectors. When a finger touches the screen, the waves are absorbed, causing a touch event to be detected at that point.

Like infrared technology, the panel is all glass, so there are no layers that can be worn, or damaged over time. This makes SAW touch screen technology highly durable and suitable for applications where high clarity is desired.

SAW touch screen technology is recommended for public information kiosks and other high traffic indoor environments.

In Australia SAW technology is usually one of the more expensive technologies. Since there are few applications where it is superior to infrared, infrared is more often the recommended solution where high durability and screen clarity is required.

Limitations of SAW Touch Screen Technology

  • Must be touched by finger, gloved hand, or soft-tip stylus. Something hard like a pen, credit card or finger nail won’t work
  • Can be affected by large amounts of dirt, dust, and / or water in the environment.
  • Relatively expensive in comparison to other technologies

Popular Brands that often use SAW Touch Screen Technology:

  • ELO

Infrared touch screen technology

Infrared technology uses a small frame around the display with LED’s and photo receptors hidden behind an infrared transparent bezel. The controller pulses the LED’s to create a grid of IR light beams. A touch obstructs the beams which identifies the X and Y coordinates.

Technology of Touchscreen 4TouchScreen Solutions supplies all popular touch screen technologies. For most applications, if the budget allows we recommend infrared technology. Whilst this technology is more expensive to produce than others, it is generally a more robust and preferred solution.

Benefits of infrared technology:

  • Can be scaled to any size without losing resolution
  • Calibration stability – no touch point drift
  • High clarity and light transmission
  • High chemical, scratch, breakage, and liquid resistance
  • High sealability from dust and liquids
  • Touch can be activated by anything including finger, gloved hand, or stylus
  • High durability since a touch is only interrupting light beams

Popular brands that often use infrared touch screen technology:

  • Nexio
  • IBM
  • ELO

Apry Nur Sudi Yanto (125150300111030)


Sound Charge T-shirt

Sound Charge T-shirt 3Orange (a telecommunications company brand France) in collaboration with GotWind (an organization working in the field of technology) has created a shirt that can transform sound waves into electricity. They call it the Sound Charge T-shirt.

The purpose is to create a solution to recharge the phone or gadget with a noisy environment like a festival or mine drilling area. So need for communication can continue to be met and does not need to be disconnected.

Sound Charge T-shirt 1

The working principle Sound Charge T-shirt is by using piezoelectric elements to generate electricity. Piezoelectric technology itself has been known since the 19th century. Piezo derived from the Greek, piezo / piezin which mean pressure. Piezoelectric commonly used to refer to a device that uses pressure to produce electricity.

Piezoelectric the easiest example is to look on the lighter. Piezoelectric crystals are used in lighters to create a high voltage power after being hit by a hammer spring. This electricity then burn the gas and creates fire.

 Sound Charge T-shirt 2

Sound Charge T-shirt using a piezoelectric film layer as a fundamental component in creating electricity. As shown in the figure, the working principle can be described as follows.

  1. Piezoelectric panels in the form of an A4-sized film layer is attached to the shirt (white part). The piezoelectric film received the “pressure” of the sound waves coming.
  2. Then, piezoelectric quartz crystal material in the film layer converts sound pressure waves into electricity
  3. The electricity produced will be stored in a small container for batteries. Later, the gadget you want in-charge stay ‘plugged’ into the battery.

To sound at the level of 80dB, the T-shirt is capable of producing electricity at 6 Watts. According to them, the noise equivalent of crowd noise in the streets of big cities. For a live performances of music, of course, as hard as it sounds (80 dB) will be easily obtained. T-shirts have also been tested on the biggest annual music festival in the UK that is Glastonbury.

Of this discovery is still not perfect. Still needs some improvement and development to be done to be mass-produced. Moreover, this is only one solution of many ways to earn alternative energy, such as solar panels. In my opinion, every innovation deserves to be appreciated.

May we as college can develop a better technology for the name of Indonesia in the eyes of the world.

Apry Nur Sudi Yanto (125150300111030)