What do device developers and design engineers need to know about membrane keypads and touch pads

Invented over 30 years ago, membrane keyboards and switches were at first ridiculed as a low-cost but unreliable input technology.  However, after decades of improvements, the membrane switch has now been established as an effective solution for many different technical applications. Today, due to unquestionable advantages, it has become indispensable for many industries. Often unnoticed by consumers, the simple keypad has now developed into a sophisticated high-tech system.