“…In recent years, there has been competition amongst manufacturers to introduce increasingly compact forms of these products that contact the hand. In the design, sometimes attention has been paid to the user's ergonomics needs to work harmlessly, effortlessly and comfortably with these products [1]; and sometimes comfort studies are done to improve the interactions with handheld devices [2], such as tablets [3,4], smartphones [5], PDA, eReaders or gaming systems [6,7]. However, not much attention has been paid to contact areas between device and hand, and how to adapt them considering the difference in sensitivity (or discomfort threshold) of the various areas in hand.…”