Perpetual Motion: the concept that keeps on giving and giving…and giving…

A perpetual motion machine is one that can do infinite work with no energy input.  Such a machine is impossible as it would violate the first or second law of thermodynamics (that internal groan isn’t likely be your last).


The first law of thermodynamics relates to the conservation of energy, so if you are not adding energy to a system, you cannot take energy out and expect the system to work indefinitely.

The second law of thermodynamics relates to entropy, defining that the total entropy of a system will always increase over time.  Some energy is always lost through friction or otherwise dissipates so that not all of the energy is produced as work.

Violating a few of the laws of thermodynamics hasn’t seemed to be a problem for countless individuals, even long before there was any way of protecting their intellectual property, and now that there is, the good burghers of IP Land have decided that such machines are unpatentable subject matter.

The purpose of this article is not to start reciting and examining the law.  It is what it is, and a simple googling will tell you so, but that does not stop inventors from claiming machines that do more work or create free energy from nothing.  Some even explicitly claim perpetual motion as an essential feature.

As a patent searcher, when I have to conduct a novelty search into an inventor’s magnum opus, and I look at the IPC (International Patent Classification) and find that there is an obscure subclass specifically dedicated to that aspect of the technology, I know things are not going to end well.

The same goes for perpetual motion, or as the Latinistas of WIPO have put it, perpetua mobilia.  There are four IPC classes that specifically mention perpetua mobilia, and a couple more that seriously think about it.

  • F03G7/10 Mechanical-power-producing mechanisms using energy sources not otherwise provided for, with a 1-dot subclass for alleged perpetua mobilia
  • F03B17/04 Other machines or engines, with a 2-dot subclass for alleged perpetua mobilia
  • H02K53/00 Alleged dynamo-electric perpetua mobilia
  • H02N11/00 Generators or motors not provided for elsewhere; Alleged perpetua mobilia obtained by electric or magnetic means

The two others are F03G3/00 Other motors, e.g. gravity or inertia motors; and F25B9/00 Compression machines, plant, or systems, in which the refrigerant is air or other gas of low boiling point, but for simplicity I am going to ignore these.

The CPC (Cooperative Patent Classification) is almost identical, except the H02N11 class has been subdivided so that the CPC gives H02N11/008 as the relevant subclass.

There are two points to make here.  First, they all say “alleged”.  They are giving inventors the benefit of the doubt before refusing the application.  Second, these classes have been in place since year dot of the IPC, way back in 1971.  These are not classifications that have expanded over time as the level of innovation in these areas demands it, and where a subclass has been added years later.  They were always there; the idea has always been doubtful.

I have conducted a search in PatBase in the four IPC and CPC classes above as well as looking for the keywords “perpetual motion” in the title, abstract or claims, for anything filed since January 2015.  There are a few other keywords that could be used, but it is useful to look for those inventors who are upfront about their ambitions.  This search finds just under 8000 patent families.  I will take an extra step at this point and remove any family where one of the classes above is not the first listed.  Any family falling into this category would appear to have utility by being classified first in a typical IPC or CPC class, and having an alleged perpetua mobilia class thrown in at the end just in case.  After doing this I am down to just over 3100 patent families of genuine alleged perpetual motion machines.

Looking at this data set, there are a few things that really stand out.

While there are fifty-seven jurisdictions around the world that can claim some passing interest in perpetual motion, the Peoples Republic of China accounts for almost half of all patent families in this field, and as with Chinese patent applications in general, the number is rising year on year.

Another stand out is that electrical devices are the predominant field of endeavour, outstripping mechanical devices by a factor of 3 to 1.  This probably reflects the modern world where renewable energy generation and storage is a growing industry, and generating free energy forever for zero cost is an attractive proposition.  These points are apparent in the ‘concept cluster cloud’ below.  This is a chart generated by PatBase Analytics that gives frequently occurring concepts or keywords found within the set of 3100 patent families more prominence, in this case with a larger font.

One last stand out is that some of these applications get granted, even when they are classified primarily in an alleged perpetua mobilia class.  In fact, almost two hundred per year are granted, as shown below.  Most of them, about three quarters, are granted in China, and it appears that the majority of these are utility patents, where there is little or no examination and a lower requirement for an inventive step.  That still leaves a substantial proportion of granted patents theoretically with unpatentable subject matter.  It may be that some of these applications had multiple inventions, and the unpatentable ones have been weeded out, or that at first glance it appeared to be a perpetual motion machine, but was not, or was suitably amended to enable acceptance and grant.

So, the question remains: what is allegedly new in the field of perpetual motion machines?

I would be loath to point out anything I thought was half serious, just in case it’s ‘the real deal’, so I will stick to highlighting a few of the more unusual patent applications in the field.

CN10456473A is a perpetual motion machine for drawing water from a low level reservoir to a higher level one using a waterwheel and siphon tube where a portion of the water siphoned is used to drive the waterwheel while the remaining portion is sent to the higher reservoir.

The interesting thing about this specification is that three quarters of it is dedicated to an essay on the futility of perpetual motion, before moving on to time travel, the space-time continuum, gravitation energy, and last of all, God.  The last quarter, without a hint of irony, describes the invention.

CN105587479A is a gravity driven perpetual motion machine based on the idea that a circular chain, where part of the chain rests on a sloping surface, and by calculating the relevant gravity force vectors, conclude that the sloped portion of the chain weighs less than the portion of the chain that is vertical, and as such the heavier part of the chain will pull the lighter part up the slope thus creating perpetual motion.

Energy generation doesn’t rate a mention for this device.  Its sole utility appears to be as a toy.

GB2547229A relates to electric vehicles, where the vehicle has two batteries.  The energy from one battery is used to propel the vehicle, while the vehicle engine charges the second battery.  When the first battery is drained, the roles of the batteries are reversed, and the second battery now propels the vehicle while the first battery is recharged by the engine, thus negating the need to stop and refuel.  There’s not much to this specification, certainly no grand theory of everything nor any delving into the nitty gritty of the laws of physics, no doubt because the idea is so obvious and useful that it needs no further explanation.

AU2016256693 was withdrawn before examination occurred.  There’s not really anything to say about this one as the title says it all, which is:

The Newton Perpetual Motion Machine is a Machine which uses the outside source of energy initially then it will work by newly discovered method. Albert Einsteins equation e=mc2 so energy is everything. But; Who made them as they are now? In the Quantum world; Everything is made of uncertain things the elementary particles So, we cannot able to say anything with absolute certainty. So, laws of thermodynamics. This machine may violate the first and second laws of thermodynamics so It might not make any general sense like a spooky action in a distance (Quantum entanglement). Energy is the law.

One thing I can say about most of these inventors is that they have some idea of the laws of thermodynamics, know that they can’t be violated, and know that perpetua mobilia do violate the first and second laws, but it does not stop them from trying, and claiming, to have achieved the impossible.