Material energy is not a scientific term. Any health benefits or effects that are claimed to come from magnets or copper are not scientifically valid and are trying to take advantage of people ( usually for $$).  For many years people thought there was some sort of mysticism related to magnets because they didnt understand how they work.

With scientists there is a saying that any sufficiently advanced technology is indistinguishable from magic. that also applies to misunderstood scientific principles. We now have very accurate and well explained models of magnetic and electromagnetic induction. Anything claiming to be anything else is simply not true. Magnets and copper are still sold as snake oil and take advantage of people.