This might be a different sort of a question.
How can I measure the slipperiness of a surface using arduino or any other microcontroller?
I want to build a pathway sort of thing which has good tensile strength and is lightweight (Aluminium perhaps? Anything better than this in abundance and is cheap?)
What can I apply on this pathway to make it super slippery, as slippery as possible so that objects just slip through under the force of gravity if the plane is inclined? What inclination angle would I need that would work for all kinds of weights?
Also how can I measure the slipperiness so that more "stuff" can be applied after rains I guess?
Edit Update: Context of use: In a small town, a big family lives in 5 buildings. 3 of them 2 storey high and 2 of them 3 storey high. All of them are owned by the same family and the family runs a set of shops on the ground floor that faces the road side. Particularly a restaurant, a convenience/general store, vegetable and fruit store, a medical store, clothing store and a small supermarket. 1 person from their family approached me as to how can they build a system that allows sharing of stock across buildings. They said they usually stock items on the top most floor and on the terrace. So he asked me whether we can build a conveyor belt to move stuff from lower height buildings to higher height buildings and use a slippery surface to move stuff from higher to lower. For example fresh vegetables and fruits are required in both restaurants and vegetable shop. So there are some common items which are required by 2 or more shops and in order to facilitate easy stocking, can we build a system that allows to move stuff easily across buildings? Weight and material of the item to be moved can be anything, ranging from 10 kg detergent bag to lightweight cotton earbuds. Maybe we can pack all things in a common casing (cardboard or plastic) so that everything is deterministic.