electro - mechanical and electronically controlled access devices are described for controlling access to a building , premises or area in a secure manner such that a subject who is deemed ineligible for access will be barred entry and may be optionally retained . the devices can contain multiple rotatable door panels , which can be positioned behind one another . the door panels can be controlled by mechanized arms or other control devices in order to control the passage through the device . the direction of flow through a device according to these embodiments is electronically controlled and may be changed at any point in time . at any instant in time , the flow through the device is unidirectional . multiple devices can be stacked together to form clusters , which can be controlled according to traffic , time of day , or other factors .