Hugging Machine

The Hugging Machine is a machine that was built by Leonard when he was 10 years old. The machine has only been mentioned in "The Maternal Capacitance" (S2E15).

Use
The machine was used to give people hugs. Because of the lack of affection from his mother, Leonard was desperate for some human warmth and companionship and thus, he built the hugging machine.

Leonard built the machine by getting a dressmaker's mannequin, stuffing it with an electric blanket so it'd be warm and he built two radio-controlled arms used to hug the user and pat and their back.

Leonard told all this to Penny in her apartment and comment that that is so sad, but it turns out that there was a sadder part, which Leonard said was the saddest part, which was that his father used to borrow the machine.