She stars alongside Bruce Willis as a sexy, physically perfect robot in Surrogates, directed by Jonathan Mostow (Terminator 3: Rise of the Machines, Breakdown), a new action/ thriller that explores what it would be like if humans were able to live their lives vicariously through robot surrogates. Aussie actress Radha Mitchell, however, would've preferred a padded butt and buck teeth.

You starred alongside Johnny Depp in Finding Neverland as the alienated wife of Peter Pan and then you took on the complex role of a woman searching for love in Woody Allen's Melinda and Melinda. You've developed this reputation for being able to delve into really complex, emotionally charged roles. But here you are battling it out in one of 2009's biggest action movies. What drew you to the film?
This isn't just a movie about fake robots - this technology is happening in real life! Hollywood is afraid of technology. We usually see robots take over the world - they have their own minds. But in Surrogates, it's not the robots that are dangerous - it's the way that humans are using them that's dangerous.

So, there are deeper themes that the movie explores, rather than just pitting human against robot?
Absolutely. Humans get so addicted to the comfort and ease of not having to leave their own homes that they stop living human lives. That's what I find so interesting. This movie explores our addiction to technology. I can't remember life without my cell phone! Technology can advance us, but it can isolate us too. You can have 500 friends on Facebook but that doesn't mean you have genuine friends in real life.

Did you have any special training for some of the amazing stunts you pulled in the movie?
I found out that I can run really fast in heels! I can jump off targets - I even hurt my leg during the filming.

Was it serious?
(Laughs) Nothing too serious, but I did get scratches. I was jumping on cars while I was wearing these super high heels. It was all quite exciting. At another point, I was driving around downtown Los Angeles and I was strapped to this bus. It doesn't sound that exciting but here I am strapped to this huge bus in the middle of Hollywood...!

You've been in the industry for a long time now - but do you have those surreal moments where you stop yourself and think: I'm in Hollywood! And I'm on top of a bus!
Yeah it's kind of ridiculous (laughs). But I guess it's what you sign up for and it's the kind of things you don't get to experience in every day life.

You're an Aussie living in LA - some would say that that's almost equivalent to being in a surrogate world. Do you ever feel the pressure to freshen your looks so you can keep getting sought-after roles?
I certainly don't look to do that. But on this film they did scrutinize they way we look. It was basically like being put under a microscope. It was a little uncomfortable. I discovered the beauty is painful! We had to get our teeth bleached - which is so painful. It made rehearsing lines really painful and it was a strange way to bond with my cast mates.

Did you have to undergo any other changes for your role?
Just the padded bras and the rest of that crap. Personally, I didn't really love that side of it but when I did enjoy playing my 'real' human character - a frumpier, plain Jane version of the character - I got to have a padded ass and buck teeth. You can't even really see how much work went into that look - but it took a while. I would've liked to spend more time with that character.

The surrogates are sexy, physically perfect mechanical representations of themselves. What would your surrogate look like?
I'd be a cat. In the movie, humans are able to have a total sensory experience through their robots. It would be amazing if I had the opportunity to feel what it would be like if I was a cat.

Why a cat?
I think it would be sexy to look and feel half human, half cat.

Surrogates is out in cinemas now.