Using finger for touchscreen devices; is it safe?

The use of touchscreen devices become a part of people daily life. Finger is used to communicate with such devices. This paper investigated the interaction between human finger and touch screen devices. A series of experiments was performed to investigate the participants' finger functionality when they press their finger on a touch screen device. The study was concluded that the pain threshold is higher than normal pressing force but for repetitive pressing the level of pain threshold will decrease.