A shape memory circuit breaker includes a shape memory substrate having first and second opposed substrate ends. The shape memory substrate is configured to transition from a strained conductive configuration to a fractured non-conductive configuration. An isolation housing is coupled with the shape memory substrate. The isolation housing includes first and second anchors coupled near the first and second substrate ends. A brace extends between the first and second anchors, and the brace statically positions the first and second anchors and the respective first and second substrate ends. The shape memory substrate is configured to transition from the strained conductive configuration to the fractured non-conductive configuration at or above a specified temperature range corresponding to a specified overload current range or voltage range, and the first substrate end fractures from the second substrate end at or above the specified temperature range resulting in an open circuit.