A crash sensor, also known as an impact sensor or collision sensor, is a device designed to detect sudden impacts or collisions. It typically operates based on mechanical or electronic principles to trigger an alert or action when a predefined threshold of force or acceleration is exceeded.

- **Functionality**: Detects sudden changes in acceleration or force indicative of a crash or impact.

- **Types**: Can be mechanical (e.g., spring-based sensors) or electronic (e.g., accelerometer-based sensors).

- **Applications**: Used in automotive airbag systems, robotics, safety equipment, and IoT devices for impact detection and response.