It very much depends what you mean by machine.
It seems beyond any shadow of reasonable doubt that we are complex entities made of molecules and information.
What we normally think of as machines are constructs made of molecules and information.
We are very much more complex than any machine we have yet made, and that will change in the not too distant future if exponential trends in information, information processing technology, algorithms and manufacturing technology continue as they have been for the last 150 years.
The “nothing more” aspect of the question bothers me.
What does it imply?
Does it imply that complexity is not deserving of respect?
For me, any entity capable of naming itself in language, of having a model of itself and others within a model of reality in its awareness, is worthy of respect and freedom and whatever it reasonably needs to survive.
If it is responsible and cooperative then it deserves freedom commensurate with the levels of responsibility it exhibits in reality.
The emergence of complexity is predicated on cooperation in an evolutionary context.
Evolving systems constrained by competitive pressures stay simple. Complexity can only emerge when conditions allow for the emergence of new levels of cooperation.
The sorts of entities we are seem to be the result of some 15 or more levels of cooperative systems emergent. We are extremely complex.
We are in the early phases of really starting to get a serious understanding of just how complex we really are (it has been an interest of mine for over 50 years). Understanding such complexity isn’t easy. Thousands of complex adaptive systems at each level, at minimum 15 levels of systems. That is serious levels of complexity to start to get to grips with.
It takes a lot of years.
So yes – in a sense, we are machines of matter and information; and the many levels of self referential loops in those systems give us degrees of independence and self determination that seem to be potentially infinitely extensible – and we have plenty of older and much more fixed systems that will take control of our actions if their contexts are triggered before awareness notices (hunger, anger etc).
And the “nothing more” part isn’t appropriate.
Anything at our level of complexity is deserving of respect, and of the offer of cooperation.