But if he is given a violent shake, or shouted at, he gets upset. He flinches, his hands clench, his breathing and heart rate speed up, and his eyes widen.
Heart Robot, created by scientists at the University of the West of England in Bristol, was designed to explore how humans react to a machine that appears to show feelings.
Holly Cave, who helped organise the Emotibots event at the Science Museum where the machine was unveiled, said: "Heart Robot looks like a cross between ET and Gollum and is about the size of a small child.
"He's half robot, half puppet. You move him around by hand, but he has innate responses that appear emotional.
"Different children react to him very differently. They either want to hug and cuddle him, and look after him like a doll or baby, or they just want to scare him."
Meanwhile Hexapod, a six-legged metallic spidery robot, was also a big hit because it could recognise and latch onto the faces of visitors who walked around it.
If a person holds Hexapod's gaze long enough what it sees is photographed and projected onto a plasma screen.
According to Matt Denton, its creator, a computer connected to a camera in the head of the robot has been trained - thanks to being bombarded with hundreds of facial images - to recognise when it comes across a face.
It then instructs another computer, which controls movement, to lock onto it and follow it around.
The robot has a starring role in Harry Potter as one of Hagrid's pets.
The organisers said the event coincided with the release of the new Pixar movie WALL-E, in which a lonely robot looks for love on a deserted planet Earth.
Ms Cave said: "Everyone's falling for the "lonely" robot WALL-E, but the idea of robots having emotions or a personality may no longer just be science fiction.
"How humans and robots might interact in the future is something that raises lots of interesting ethical and moral questions."
Emotibots is free and takes place in the Science Museum's Antenna gallery from today until Thursday.