Hello Everyone,
I have been thinking about trying to make a ESP8266 board and SD Memory fit into a small form factor say 15mmx15mm the board would then be encapsulated. That is the easy part. powering the board I would prefer to have biocompatible wires to a inductive charging loop implanted on the bottom of the forearm with the board on the top of the arm. To power the device I would take a small Li-ion power pack and a inductive coil strapped to the underside of the fore arm much like a old ipod case. my concerns are heat generated by the esp chip and signal interference from the inductive power loop. Does any of this sound possible?
My first concern would be what kind of range would you get when the wifi antenna is encased in relatively low resistance flesh. Personally I wouldn’t want a 2.4ghz transmitter in me.
Heat could certainly be an issue. Datasheet says it needs 170ma at a 50% TX duty cycle…File transfers would probably get higher than 50% DC. Then you also have the electronics to regulate the voltage coming from the inductive loop generating heat.
The loop would not be operating anywhere near 2.4ghz so signal interference would be minimal, though just the metal in the loop itself, if placed close to the wifi antenna may have some implications on the wifi.
I mean from a technical standpoint, I think your ideas is possible. How well it would work is debatable. It would be much easier to carry a Pi Zero W and a battery in your back pocket. 
The Pi is the easiest but it can be removed and is not hidden. It would not need much range what ever would be accessing it would be close (Cellphone, laptop) I could limit the power output to keep heat down but the DC-DC Converter for the inductive loop would still generate the most heat. I think 2.4ghz would be very low risk if in the arm and power output was kept as low as possible. Thanks for the response!
What are you going to do with a “file server” in your hand?
More like a hidden wireless Flashdrive.