Amal Graafstra has been biohacking since 2000. For those not familiar with biohacking, it is the implantation of a device to interact with technology. The basic ones I have heard of are magnets embedded in finger tips. Other examples involved injecting a small RFID into your skin. That is what Amal has done here. His company, Dangerous Things, sells self inejctable RFIDs. It is considered body augmentation. Coupled with the right technology you can unlock the door to your house with just a wave of your hand.
Amal created a safety mechanism and installed it into an FNH PS90. The trigger is physically locked unless his RFID or any programmed RFID unlocks the safety mechanism. One benefit to implanted RFIDs, is that it is very difficult to misplace the RFID if it is inside you. Most of us, myself included, are always skeptical of smart gun technology. However Amal does acknowledge those issues. He says that this type of safety mechanism could be made to be fail-safe or fail-secure. In a fail-safe setup, the gun will be unlocked in the event of the battery dying that powers the safety mechanism. Another option is to make it fail secure where the safety is still engage even without power. One issue that was not mentioned is how long is the gun unlocked for? How quickly does it lock itself once the registered RFID wearer is no longer in proximity to the sensor in the gun?
I can see the attraction to having technology help aid a firearm owner however the same issues can be addressed with a simple gun lock or safe. It may be analog but it still works.