But that has all changed, of course. The modern smart phone only has a handful of physical buttons. Android and iOS are operating systems designed for use without a mouse and keyboard, not just touch as an afterthought. But the quality of a touchscreen is hard to quantify. You can describe its technology—capacitive, resistive, multi-touch, stylus—but beyond that everything comes down to 'feel'. So what makes one better than the other?
A Bit of HistoryTo understand where we are with touchscreen technology, let's look back at where we've come from. The first touchscreen was developed in 1973 by Dr. Sam Hurst, a physics professor working at Oak Ridge National Laboratory. Looking for a method to directly input points on a graph, Hurst created the resistive touch screen in which two thin layers of conductive material form a circuit when a force presses them together.
first multi-touch screen was developed by Bell Labs' research Bob Boie in 1985. It used a capacitive array of touch sensors laid overtop a CRT display. A capacitive surface is a conductive surface with a voltage applied across it. The human body’s natural capacitance causes a local build-up of electric charge when the surface is touched, and the position of the disturbance of the field can be determined. Yet, despite the technological accomplishment, Bell Labs was unable to find an outlet for multi-touch and the project was tabled.
Incremental innovations were made in the area of touchscreens throughout the '80s and '90s, but technology still was unable to make in-roads into consumer products. Standards of today's touch interfaces were established along the way, however. The "pinch" gesture to zoom, scale, and move objects was pioneered by Myron Krueger in 1984.
The first smart phone, IBM and Bell South's 1992 Simon was the first smart phone and integrated a single-touch interface to control most of its functions. Wacom successfully combined a multi-input pen and puck with a position locating and pressure sensing surface. The flick gesture was implemented in a digital whiteboard in 1999, while various research labs and universities worked to establish a vocabulary of touch gestures at the turn of the millennium.
first iPhone commercials did not showcase people out and about using the phone, but a single anonymous pair of hands set against a black background, scrolling, swiping, and tapping through the phone's features.
Thankfully, Apple's patent claims over multi-touch have yet to be enforced ( if at all enforceable) and new smart phones and portable devices from a variety of manufacturers have placed us in a touch paradigm. But not all touchscreens are created equal.
What Differentiates Touchscreens?
What is it, then, that influences the overall experience of a phone? It's all in the details. The calibration of the touch sensor, the sampling rate, and noise-filtering turn your intentions into actions. As Wired's Priya Ganapati details, Apple is a stickler about its touch sensitivity, using "a 12-volt power source for the sensing lines in the touchscreen sensor, versus the 3- to 5-volt power source that most other component manufacturers have." In turn "that higher voltage drive takes a toll on the battery life because it uses up more power, but it also translates into more accurate sensing."