Get this very nice working model engine here, choose a configuration:
From EngineDIY: BUY NOW: Stirling Engine
From EngineDIY: BUY NOW: Stirling Engine with Generator
From EngineDIY: BUY NOW: Stirling Engine Simple Vehicle
Stirling Engine: an elegant model of an external combustion heat engine with dual reciprocating pistons which operates by cyclic compression and expansion of air. Heat one cylinder with the cute little alcohol burner and this model gets up to speed quickly. Pyrex glass allows one to view the hot cylinder in operation (shown here in slow motion) and this version of the model includes a small generator to convert some of the mechanical energy into electrical energy which then powers some LED lamps. This design is attributed to Scottish engineer Robert Stirling back in 1816- a working piece of the industrial revolution for your desk top!
This dinosaur themed heat engine available here:
From Amazon: BUY NOW: Drinking T-rex Desk Toy
Get also: the related Drinking Bird Heat Engine
Drinking Dino Heat Engine: So what physics presents did you get this year? I got this Dippy Dino heat engine- where cooling by evaporation at the head leads to lower pressure in the top bulb such that the dichloromethane fluid (colored green) rises up the neck making the T-Rex top heavy and the dino tips over dipping its face in the water and letting the fluid return to the bottom bulb. The process repeats as long as the top stays wet. A fun and silly variation on the famous drinking bird physics toy- and the T-Rex was a closely related ancestor to the dinosaurs that live today- birds!
This device available here:
From Edicational Innovations: BUY NOW: Horizontal Hand Boiler
Horizontal Hand Boiler: liquid-gas phase transition. The boiling point of dichloromethane is slightly below body temperature and heat from a hand will induce vaporization of the liquid which increases pressure in one bulb pushing the red (dyed) liquid through the glass pipe to the other bulb. The process can repeat by switching the hand to the other side, but as both sides heat up the transfer is less vigorous. An inexpensive toy demonstrating phase changes and other thermodynamic physics.