I could be wrong, but I don’t believe the mark of the beast is a micro-chip or anything like that. I believe it is what is in your heart and mind(forehead) and what your actions reveal(right hand).
Scripture says you wont be able to buy and sell good without the mark. I don't think we will have a machine reading the hearts or actions and man to allow them to buy and sell goods.
Also, scripture says that one of the punishments will be sores developed by those who receive the mark. So, they tattoo or implant something in the people and the body rejects it and develops sores and the like. This is what I think.