Mobile World Congress in Barcelona is naturally heavily-focused on smartphones, mobile accessories, and apps, but if you pound the halls for long enough, you’ll find lots of interesting technology that doesn’t fall cleanly into those categories. We uncovered some intriguing new gadgets and technologies at MWC 2018, so here are our favorites from the show.

Modius – Weight loss headset

What if you could suppress your appetite or speed up your metabolic rate by wearing a special headset that gives you small electric shocks behind the ears for an hour a day? It may sound crazy, but that’s the promise of Modius, which sends low-power electrical impulses to your vestibular nerve, to activate your hypothalamus.

We first wrote about Modius before its successful Indiegogo campaign. With 4,000 headsets shipped and mounting evidence that it works, we’re about to put it to the test ourselves in a full review, but we took the chance to try it out for a few minutes at MWC and talk to one of the highly-credible neuroscientist founders, Dr Jason McKeown MD.

It feels just like it sounds, a tingling sensation via the electrodes which are attached to the bony area behind your ears that gets stronger as you move up through the 10 levels. It also creates a feeling like you’re swaying or rocking, which wears off instantly when the Modius headset is turned off. The science behind it is sound, but the clever thing about Modius is that it achieves a known effect without the need for invasive surgery.

Weight loss is big business, so interest in a gadget like this is no surprise. We’ll need to use it for a few weeks to put it through its paces and see what the impact is, but we’re hopeful about the technology. Stay tuned for our in-depth review.

PureLiFi – Internet through light

We’re big fans of PureLiFi, in fact the Edinburgh-based company won our cool tech award at MWC last year for its internet through light technology. At MWC 2018 PureLiFi has been showing off its receiver technology integrated into a Dell laptop, and a case for the Samsung Galaxy S5.

As the spectrum crunch approaches, the ability to complement Wi-Fi networks with Li-Fi systems will become more and more essential. We streamed a video from Digital Trends onto the Galaxy S5 via an overhead strip light and it worked flawlessly. The connection is currently capable of 42Mbps up and down.

Further miniaturization and integration into smartphones is on the horizon and we hope to be connecting to the internet on a flagship phone using Li-Fi within the next three years.

Elliptic Labs – Ultrasound gestures

In the past, ultrasound pioneers Elliptic Labs showed off how ultrasound technology can replace proximity sensors in phones, turning the screen on when your hand or face is close to it. That tech made it into the Xiaomi Mi Mix handsets, enabling the manufacturer to shave bezels down. Elliptic Labs also added some other gestures for things like tweaking the volume and snapping selfies.

At MWC 2018, we caught up with the team to see their newest demo, which enables you to control a smart speaker and a light with simple gestures that work from a short distance. By double tapping with your palm you can activate Alexa, and a single palm tap can cut it off, all without having to touch the speaker or utter a word. They also had a light that you could brighten by holding your hand at one side of the speaker, or dim by holding it at the other side, something that could just as easily work with volume.

The devices they showed are just prototypes for now, but we found the ability to stop Alexa in midstream by holding up our hand really useful, so we hope to see it integrated into an actual smart speaker soon.

Energous – Wireless charging at distance

We’ve been excited about the prospect of truly wireless charging for a few years now – the idea that your phone might charge up in your pocket or your smartwatch while it’s still on your wrist. It would be great to be freed from cables and charging pads, but mid-field charging has remained elusive so far. After meeting with Energous at MWC we’re convinced that it’s coming, but we still don’t know when.

The demo they showed us involved a smart speaker prototype set up as a transmitter, capable of sending power via radio frequencies to a phone, a smartwatch, and a pair of wireless earbuds at a range of up to 3 feet. The top of the speaker also doubled as a near-field charging pad, much like Qi wireless chargers.

Energous recently secured FCC approval, confirming that the technology is completely safe, and announced the first consumer product set to use it – which, somewhat surprisingly, turned out to be smart underwear called Skiin. Chip manufacturer Dialog is also working with Energous which could allow for much easier adoption of the technology as device makers will be able to buy a chipset that supports it.

Both Energous and Dialog were tight-lipped on partners, but you can imagine a company like Apple with an ecosystem that includes speakers to act as transmitters and phones, smartwatches, and wireless earphones that need charging would be a good fit. However, we fear it may be a couple of years yet before this goes mainstream.

Ossia – Wireless charging at distance

Another player in the mid-field wireless charging space is Ossia, and Chief Technology Officer Hatem Zeine gave us an impressive demonstration at MWC. The technology transmits power via radio frequencies at the same 2.4Ghz as Wi-Fi, but a different channel, so it doesn’t interfere. The device receiving the power sends out a signal that can bounce off surfaces like walls, tables, and windows, but is absorbed by the human body or liquids. The transmitter replicates the path of successful signals to send power back, and it checks 100 times per second, so it’s not washing you or other people in the room in power.

With two large transmitters set up at one end of the room, we saw a receiver unit light up. To prove it wasn’t just coming from the box, Hatem held another receiver in the path and then moved it around and blocked it to demonstrate the path of the power. The transmitters are big and they can send out around 10W, but the receiving device only gets around 1W. That can be boosted with multiple transmitters.

Next, Hatem plugged in a Samsung Galaxy S7 and showed it charging up, then he moved to the back of the room, showing that the phone could keep charging, even at a distance of around 10 feet or more. The charge rate does go down the further you move away, but it’s impressive to see it working at distance, and it also continued to charge when he put the receiver in his pocket.

Imagine the transmitters hidden in ceiling tiles when you walk into Starbucks, for example. Your phone or smartwatch would charge up without you having to do a thing.

There are other applications — we saw Ossia’s Forever Battery at CES. It is the same size as a standard AA battery, but can be charged wirelessly at distance and never degrades because there’s no need for a chemical reaction inside.

The hitch is that Ossia has yet to secure FCC approval, but Hatem is confident it will, and they are in talks with several manufacturers about integrating the technology into chipsets and devices. We’re looking forward to the day we no longer need cables, but it’s still impossible to predict precisely when it will come.