is the pad design or concept patented
Depends on the claims (and only on the claims). If you claimed the specific pattern then some other pattern would be OK. If you claim the principle (i.e. pads joined with tracks with 0.1mm gaps) then that would cover any pattern with 0.1mm gaps. The more general your claim the harder it is get it accepted, and it is very easy indeed to make a claim with a bunch of holes anyone can drive a truck through. Thus a patent agent is usually good value for money if you're serious about a patent.
OTOH, you might just want to be able to say "my patented product" and not give a toss if anyone else rips it off -
they won't be able to claim their knock-off is patented (unless they think up their own one). In such a case, a patent agent is wasted money, as may be the patent (depends what it's worth to your ego).
In this case, I would think that there is plenty of prior art to make a reasonably generalised claim impractical. But you could probably get quite specific and acquire patent status that way. Or, if it's just for a kickstarter project (i.e. the sales period is limited and not long term), shove in any old rubbish and say it's "patent pending". By the time it's rejected you'll either have your money or given up and be on a different scam