“…The operating principle of many machines, devices, sensors, and processes is mechanical vibration and, for the highest energy efficiency, these systems often operate in one of the normal modes of vibration. Some examples are ultrasonically assisted cutting (Babitsky et al, 2004), atomic force microscopy (AFM) (Okajima and Sekiguchi, 2003;Kuroda et al, 2008;Yabuno et al, 2008), rotary drilling (Batako et al, 2003), a pipe-crawling robot (Li and He, 2007), vibratory machines (Kurita et al, 1996a(Kurita et al, , 1996bKurita and Muragishi, 1997), vibratory material transportation (Kurita et al, 2003), pick and place robots (Babitsky, 1995), self-excited biped mechanisms (Ono et al, 2001(Ono et al, , 2004, flutter wing mechanism (hypothetical model of insect wing) (Ono and Okada, 1998), bio-sensors (Lee et al, 2007), strain and stress transducers (Zook et al, 1996;Kwasniewski et al, 2012), mass sensing (Yabuno et al, 2013), mass measurements in microgravity conditions (Mizuno et al, 2009), electrostatic field sensing (Kobayashi et al, 2012), etc.…”