Our project improves the safety and reliability of liquid nitrogen cryogenic dewars used to store biological, medical, and research samples. Traditional lids used for dewars do not track when they are opened, tilted, or handled incorrectly, which can lead to delayed detection, sample loss, and safety concerns. To solve this, we designed a self-powered smart dewar lid that detects lid movement, monitors system activity, and sends real-time Bluetooth alerts. The system uses an ESP32, motion sensing, temperature sensing, battery power, and energy-harvesting concepts to make cryogenic storage smarter, safer, and easier to monitor.