Blank stare
A blank stare is the look on a fembot's face that can help show how inhuman it is. It can show a complete lack of expression when used by an actress portraying a robot. Wide, unblinking eyes and an absence of movement can make the effect quite strong.
Notable blank stares
The "Elevator Girl"
One of the first fembots seen in the movie Westworld, the Elevator Girl shows that she is a robot when she stops moving and stares unnaturally forward.
Maria
As one of many fembots named Maria, Sally Yeh had quite a talent for portraying an emotionless robot. One of her strong points was a perfect blank stare.