Even the largest video displays are still missing one physical sense that is very important to love: touch. Both sexual and non-sexual physical touch help couples bond, not least by releasing a social chemical called oxytocin in the brain, Young said.

In 2006, Time magazine called the Bluetooth-enabled “hug shirt” one of the best inventions of the year. The shirt is embedded with devices that can sense and recreate the strength, warmth and heartbeat of someone’s embrace. If hugger and huggee both wear the shirts, which are linked to their cellphones, they can send touches to one another’s torsos and arms, to any location their phones could normally make calls. If one party doesn’t own a hug shirt, he or she can still send a hug using software called HugMe.