Definitely. Especially since in either case, you have to put the device in a predetermined place.

> the emitter could be aimed at a wider charging surface, such as a counter or tabletop, and charge a smartphone placed anywhere on that surface.

And because in order to notice that the device is there, they have to also make it emit chirps

> The researchers programmed the smartphone to signal its location by emitting high-frequency acoustic "chirps." These are inaudible to our ears, but sensitive enough for small microphones on the laser emitter to pick up.

End result: a phone that chirps all the time (you can't hear it, but maybe your dog is annoyed or your security system is triggered), in order to let the charging system notice that it's sitting in a predetermined location, so that it can fire a laser at it, which needs safeguards to keep from hurting you. Also this method is apparently inefficient, given that they need a heatsink for the laser.

How about no chirping, no lasers, and we just make plugs that are easy to use? (The old round barrel-style plug on my ancient flip phone was easy to plug in, even in the dark.)

There are lightbulbs that form mesh networks using lasers. I forget the name but I recall it being on HN last year so it must be true! A quick googling finds something similar https://techcrunch.com/2015/09/14/linux-light-bulbs-allow-de...

If lightbulbs can provide wireless power to devices in the room that would be awesome and have practical applications even if it can't charge something as power-hungry as a phone very quickly.

Lightbulbs already do this: solar panels work perfectly well under bulbs of many type.

Typical 5 watt solar panel is 25x25 cm. That 5 watt is generated under ideal conditions, i.e. in sunlight, measuring about 100 kilolux. Bright indoor lightning is 1 kilolux, i.e. the "indoor solar panel charger" would take ~6 m² (assuming ideal spectrum).

They don't use lasers.

I can't believe true effortless phone charging still isn't solved. The capacity of a phone battery is about 8 Wh, which would mean that an "ambient" charging solution in a bedroom would need to provide 1W of charging to be feasible. We already know that we can put decent antennas for microwaves inside phones at low cost (e.g. WiFi), so what's needed is some form of tracking beamforming from the transmitter to get reasonable efficiency. Even if only 10% efficiency can be achieved, that should be a viable product (leaving aside the moral/environmental aspect of energy waste).

I guess part of the reason why it doesn't exist is non-technical hurdles, FCC and radiation fears.

I see what you're saying. We all want to improve technology here right. But I don't find it a great deal of effort to leave my phone on a charging mat when I go bed already. I think we're already at an efficient cost of effort over financial cost of an even more effortless technology already.

First off, I'm not saying I want this tech, I'm saying it would do well in the marketplace if it existed. Second, the 'effort' is not the physical act of plugging in, but rather the mental act of remembering to. Plus the potentially huge downside of running out of battery in a precarious situation.

for me, it’s not about when i go to bed. that part’s easy already; it’s about when you’re at a friends house, or work, etc for longer than you expect and your battery starts to go flat. in this case, you think “i should have just charged my phone; i was next to a USB port all day”. it totally eliminates these situations once lightbulbs with charging become common place because you just show up and your phone starts charging without thinking about it

It's very likely that the low-tech alternative just catches up way sooner than the (objectively better) high tech solution becomes viable.

The low tech in this case is that your friend probably has a compatible charger, and it's probably even already lying around so you can just plug in without even breaking conversation.

(There are a number of incompatible standards out there, but wireless charging would also be beset by competing standards)

Really there are only three standards I can think of - micro usb, covering probably 80%+ of devices, whatever the current becoming popular. That's way better than it used to be.

I suspect ubiquitous charge pads will get us most of the way there a long time before any sort of long distance wireless (especially if e.g. the EU mandate a single charging standard as they did with micro USB). If they are everywhere, it's relatively easy to remember to put your device there, and forgetting to do so doesn't matter most of the time if/when you can get a meaningful amount of charge in just a few minutes.

Even just wireless contact charging. Battery life isn't a real issue on phones these days, as long as you plug it in when it's not in use.