An isolator device comprises a first mount coupleable to an input structure subject to shock and/or vibration energy, a second mount coupleable to an object to be isolated (e.g., an electronics device). A flexure structure is coupled between the first and second mounts, and comprises a plurality of parallel flexures, a series of flexures, and a plurality of transition portions, all defining an isolation path between the first and second mounts. The parallel flexures are tuned to resonant frequency to attenuate shock and/or vibration in an axial direction relative to a normal axis. The series of radial flexures are tuned to resonant frequencies to attenuate shock and/or vibration energy in both radial directions relative to the normal axis. The isolator device can be a single piece of metallic material. An elastomeric damping material can be disposed within openings defined by the flexure structure to dampen response at the isolator's resonant frequency. Associated systems and methods are provided.