Abstract: A passive infrared (PIR) sensor system, includes a PIR sensor configured to produce an output signal in response to receiving infrared (IR) radiation, an electronic shutter positionable in a field of view (FOV) of the PIR sensor, wherein the electronic shutter includes a liquid crystal (LC) material, wherein the electronic shutter includes a first state providing a first transmissivity of IR radiation through the electronic shutter and a second state providing a second transmissivity of IR radiation through the electronic shutter that is less than the first transmissivity, and a shutter actuator configured to apply an actuation signal to the electronic shutter to actuate the electronic shutter between the first state and the second state.

Abstract: An HVAC register airflow control system and an air flow control method are provided. A housing of the system is in fluid communication with an air source for supplying an airflow. The housing includes an air outlet to the enclosed space. A detection sensor detects occupancy information of the enclosed space. A controller generates a control signal based on the occupancy information and controls the shape change of a damper made of a shape memory material. The damper is controlled to switch between a first operative configuration for preventing the airflow from entering the enclosed space and a second operative configured for permitting the airflow to enter the enclosed space.

Abstract: An HVAC register airflow control system and an air flow control method are provided. A housing of the system is in fluid communication with an air source for supplying an airflow. The housing includes an air outlet to the enclosed space. A detection sensor detects occupancy information of the enclosed space. A controller generates a control signal based on the occupancy information and controls the shape change of a damper made of a shape memory material. The damper is controlled to switch between a first operative configuration for preventing the airflow from entering the enclosed space and a second operative configured for permitting the airflow to enter the enclosed space.