A bodyhacking scientist who had a NSW Opal card chip surgically implanted in his hand has pleaded guilty to fare evasion because he couldn't produce the travel card when confronted by a Sydney train inspector.

Meow-Ludo Disco Gamma Meow-Meow, formerly known as Stuart McKellar, pleaded guilty in Newtown Local Court on Friday to attempting to travel without a ticket and not showing a ticket for inspection in August 2017, despite having tapped on using his implanted chip.

Mr Meow-Meow, 33, had cut down the Opal chip, had it encased in biocompatible plastic and then implanted it just under the skin on his left hand by a piercing expert in April 2017.

His biohack made headlines around the world in the hours that followed the operation but Transport for NSW warned it would cancel cards that had been tampered with.