You do not want to give out the details, that is fine. However if you want those knowlegeable people to be interested and explore collaboration with you, I am afraid you have to say a little bit more.
Perhaps you could just list out the possible technical challenges without functional specifcations, such as the requirements on sensors/interface, signal conditioning, power supply, display, actuation, data communication, etc., and even manufacturing cost.
I trust many will be interested to help, even without a dinner (could be a costly one as many are thousands of kilometers away from you :>)