So I was thinking about this TNG episode where Wesley and Picard are stuck on a desert planet with some other guy. They have no water, and no food. Then I got this idea: portable food and water replicator. It would attach to a backpack, and it would run on natural energy, but here’s the problem, scientifically, what would this energy be? Also, would it be possible? It absorbs energy and somehow clones food. It has the food recipes built in, although you can program new recipes. All shuttles are equipped with a portable replicator and first aid kit. Thanks
Replicators in general are held to be the holy grail for post-scarcity economy. Would you indeed be in want for anything?
So the implications of Star Trek technology is never really pursued beyond the requirements of the show - it is intriguing however to imagine the myriad implications of the technology depicted and take them to their conclusion.
Your personal replicator:
- Converts energy to matter. As Einstein theorised, energy and mass are interchangeable, but not necessarily in a useful manner. The key is control: according to the ratio E = mc2 a light lunch may require colossal amounts of energy (a sandwich of 250g requires 22,468,879,468 MJ of energy or roughly 5.4 1xMegaton Fusion Bombs). Holding this quantity of energy is unfathomable, and very very dangerous. Tripping over a rock and dropping and breaking your replicator would not be ideal at all.
- Potentially matter to matter. As an alternative, your replicator could 'reconfigure' matter to a new form. We do this today, with 3D printers using chemical processes. If you were to use Nuclear processes instead, then you are still talking huge amounts of energy, but perhaps more controllable as you are only converting small amounts at a time. However your replicator to make a light lunch has the capability to become a powerful weapon, create tremendous energy, and presumably can make any material needed. An error, or misalignment, or misuse (intentional or otherwise) could have colossal implications.
I think a personal replicator would place so much capability and power in the hands of one individual it would really be quite dangerous. Like a kid playing with a handgun, a person with a personal replicator has power over an enormous region around them, to such a degree I'm not sure if I would actually want to live in that future.
However, mobile phones and iPads are now a reality as Star Trek writers predicted - so perhaps this is inevitable.
If I know my swirly lights and sound effects, replicators use transporter tech. Pocket sized transporters would solve even more problems. There must be some in world reason they can't be shrunk.
The star ships have essentially limitless power. I suspect the power requirements for transporters or replicators would be immense. You could not hook one to an Exercycle and make a meatball sandwich.
But if it works for the story, great! Mr Fusion power source, pocket teleporters (careful with those! You don't want it to go off in your pocket!), all good!
PROTOMATTER and POWER PACKS:
Infinite capacity to make stuff sounds wonderful, but is very disruptive to stories. I can see why you want your device potentially powered by local power, but I have to agree that the likely power needs of such a device would be extreme. So as I see it, you have a couple of choices to make, both of which need some handwavium. Star Trek tech is full of handwavium, though.
- First, you can have some kind of extreme battery (dilithium capacitor?). This doesn't need a lot of hand waving, and I can see the drama as people try to wire a shuttle to the device to have enough power to replicate phasers, or alternatively drain their phasers to replicate food vs hunting. It doesn't get you your charging the device with local power.
- Secondly, if your replicator has a handwavium source of undifferentiated matter (protomatter), then the limit becomes how much protomatter your device holds. Normally a device like this would have enough power to make as much stuff as it would have the protomatter for, but perhaps it was damaged and now holds only a small charge. Perhaps it is attached to your shuttle, but the shuttle won't deliver operating power anymore. Depending on the nature of the damage, you might be able to only replicate small things, or wait a really long time for stuff, or the computer is damaged and they can only replicate pure things (like a mass of lysine, then tyrosine, then sucrose) because they can hand program them.
Both options have opportunities for good drama. Making the equipment the center of the story distracts from characters, and both put limits on what your device can make. The first is simpler and needs less explanation, but I think the second matches your question better. The choice is yours.