In this paper, we introduce ViPSN-E: a transient-motion-powered IoT sensor node. It carries out motion detection and wireless communication by making good use of the energy harvested from an instantaneous motion. In our design, a piezo-magneto-elastic structure, which is composed of a low-cost piezoelectric cantilever and a pair of magnets, is used to induce a plucking excitation and power generation under a transient and one-way movement. An energy management circuit, which is composed of a self-powered synchronized switch harvesting on inductor (SP-SSHI) interface circuit and a voltage regulator is utilized for efficient energy conversion. Through the sophisticated collaboration between mechatronic design and computer program, the motion information can also be identified and sent out by a wireless communication module. The cyber-electromechanical synergy among mechanical dynamics, power conditioning circuit, and the low-power embedded system is emphasized towards the successful implementation of such a motion-powered IoT device. The prototyped ViPSN-E has done a good job by making good use of the energy associated with each transient plucking motion. With only one plucking excitation, the system can realize motion detection and several rounds of wire-less transmission. The study on ViPSN-E provides valuable guidance towards the self-powered ubiquitous motion-sensing systems.