A locking apparatus comprises a sliding member, and a first memory alloy wire configured to engage the sliding member to exert a first force to move the sliding member in a first sliding direction to a locked position when electrical energy is applied to the first memory alloy wire. The locking apparatus further comprises a second memory alloy wire configured to exert a second force to engage the sliding member to move the sliding member in a second sliding direction to an unlocked position when electrical energy is applied to the second memory alloy wire. The apparatus further comprises a position limiting structure. When the sliding member is moved to the locked position, the position limiting structure holds the sliding member at the locked position. When the sliding member is moved to the unlocked position, the position limiting structure holds the sliding member at the unlocked position.