Hi Guys,
I'm totally new here but wanted to ask some advice, we have been tasked to create a robot to carry a coffee cup over a certain distance without using power! Well electric or wind up? What can we do?
Thanks,
Sean
Think outside the proverbial box?
It seems you should make a list of all the different types of stored energy you can think of. Once you do that, figure out how easy/hard it would be to turn each form of stored energy in to movement.
Sitting here thinking lets me entertain the thought of a large “silo” of water supported above your mobile base with a manual valve to control whether the water flows or not. Let the water move a water wheel which could directly drive a mobile base. Don’t forget to have a resevoir for your falling water. A fall hazard due to the movement of a cup of coffee would be bad. 
electronic robots
Electronics robot are easy to program. Batteries are needed to store enough energy to power servos anyway, but what charges the batteries can be anything!
- inducted current
- photovoltaic cells
- spring dinamo
- sugar in the coffe
Or it can be propelled by external engines, like
- kicks
- store safely coffee and then launch by hand
- a slope
- another robot pushing it
- catapult
As a general point it becomes easier if the cup doesn’t have to be delivered safe and can be spilled or ruthlessly launched against a wall:P
Think classic
Hero of Alexandria invented a vehicle that worked with weights and ropes, a very crude “programmable” machine.
More details needed…
More details needed…
I’m thinking Sterling Engine!
I think that you should google “sterling motor” or “sterling engine”. It is a thermal based engine that may be able to convert the heat from the coffee into mechanical work.
RE
Use Lego’s, they have an assortment of options in their “scientific” line of Lego parts, including solar panels, wind up motors, and all kinds of things. Not to be left out - their awesome robotics sets. Plus its easy to redesign, reconfigure with these amazing little parts.