LH13420 - In light switches, in relays, on car batteries and in light bulk sockets
– many devices require a well conducting contact between two metals, at
the least possible cost and effort. Up until recently, it was common
practice to assume linearity between conductivity and normal force – in
other words, it was believed that one would have to press twice as hard
if one wished to channel the double amount of current. In our paper
though, we showed that the characteristic of the surface roughness has a
significant influence upon this behavior by altering the surface's
contact stiffness. With the help of computer simulations, we compared
surfaces which had a rather fuzzy look to more wavy ones and found out
that the later performed significantly better at low forces as can be
found in most technical applications.
A new, brief formula will help technicians and engineers estimating the
electrical resistance by taking into account the surface characteristic
from their manufacturing method. A better prediction may help them save
material or abandon a costly surface treatment.
