A vanadium dioxide (VO2)-based threshold switch device exhibiting current-controlled negative differential resistance (S-type NDR), an electrical oscillator circuit based on the threshold switch device, a wafer including a plurality of said devices, and a method of manufacturing said device are provided. The VO2-based threshold switch device exhibits volatile resistance switching and current-controlled negative differential resistance from the first time a sweeping voltage or voltage pulse is applied across the device without being treated with an electroforming process. Furthermore, the device exhibits substantially identical switching characteristics over at least 103 switching operations between a high resistance state (HRS) and a low resistance state (LRS), and a plurality of threshold switch devices exhibits a threshold voltage VT spreading of less than about 25%. The threshold switch device may be included in an oscillator circuit to produce an astable oscillator that may serve as a functional building block in spiking-neuron based neuromorphic computing.