The lock-powered-by-key exists: <a href="http:&#x2F;&#x2F;www.cyberlock.com&#x2F;access-control&#x2F;cyberkey-smart-keys" rel="nofollow">http:&#x2F;&#x2F;www.cyberlock.com&#x2F;access-control&#x2F;cyberkey-smart-keys</a> . The power and signaling go through metal contacts rather than wirelessly.