This paper summarizes some studies performed by the author's group on energy-recycling semiactive vibration suppression using piezoelectric transducers embedded in the vibrating structures and shunted on switched inductive circuits. Basic idea of this method is to suppress the vibration by controlling the switch in the shunt circuit, which was first introduced by Richard C., et al. This idea has been upgraded by introducing (1) a multiple-input-multiple-output (MIMO) control method for the switches in the shunt circuits, (2) a self-sensing method to estimate the state of structure from the voltage across the piezoelectric transducer, so that any additional sensors can be neglected, and (3) a self-powered shunt circuit that performs the semiactive vibration suppression without any power supply. Several numerical and experimental results showed that the method works well against transient, sinusoidal, and random multi-modal vibrations and suppresses the vibrations effectively. It was also shown that the method is very robust, and, with it, the system is always stable. Studies for various applications of this method are also discussed.