With the continuous development of robotics and artificial intelligence, how to make robots look less scary and unsettling, and more friendly and human-like, has become a hot topic in the field of research and development. Now, federally funded researchers claim to have developed a robot that can mimic the facial expressions of its conversational partner. In a recent paper, researchers funded by the National Science Foundation explained how they built the latest version of their robot, "Emo," and how they made it more responsive to human interaction. At the beginning of the paper, the researchers pointed out the importance of human smiles in social mirroring: "There is no gesture more likable than a smile. But when two people smile at each other simultaneously, the effect is amplified: not only do both parties feel mutual, but the fact that they can smile at the same time likely indicates that they can correctly infer each other's mental states in advance." The researchers' new robot is a humanoid facial robot. This is not their first robot. The previous version of the robot was called "Eva." However, the researchers claim that Emo is significantly more advanced than Eva. Emo's goal is to achieve what the researchers call "co-expression," which is to simultaneously mimic the facial expressions of a human conversational partner. To achieve this goal, the researchers developed a predictive algorithm that was trained on a large dataset of human facial expression videos. The researchers claim that their algorithm can "predict the target expression they will produce based on the initial subtle changes in their facial features." The researchers then state that the algorithm will convey the desired facial configuration to the robot's hardware in real-time. In practice, making a robot produce facial expressions is another matter. The various facial configurations of the robot are driven by 26 different motors and 26 actuators. The researchers state that most of the motors are "symmetrically distributed" - meaning that they are designed to produce symmetrical expressions - except for the motor that controls the robot's chin. Three motors control the robot's neck movements. At the same time, the actuators allow for the creation of more asymmetrical expressions. Emo is also equipped with interchangeable silicone "skin," which is attached to the robot's face using 30 magnets. The researchers note that this skin can be "replaced with different designs to change the appearance and perform skin maintenance," allowing for customizable facial features. The robot also has "eyes" equipped with high-resolution RGB cameras. These cameras allow Emo to see its conversational partner and mimic their facial expressions.