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"connect to WiFi" is not remotely accurate. It should be: "Reflect wifi signals in a predictable pattern." This technique, while impressive, requires custom har
by teilo 9y ago
"connect to WiFi" is not remotely accurate. It should be: "Reflect wifi signals in a predictable pattern." This technique, while impressive, requires custom hardware/software to detect and interpret (presumably via filtering and a fourier transform) the back-scatter signal.
- comboy 9y agoYup, only plastic is also misleading since they need some conductive antenna. It's still very interesting and impressive, but somebody please fix the title.
- teilo 9y agoThis is really just a form of passive radar. It's using ambient signals instead of an active beam, but the analysis techniques used are essentially equivalent. It's like stealth technology in reverse. You are intentionally creating a recognizable radar signature.
- deleted 9y ago[deleted]
- jackhack 9y agoAll this to replace a slip of paper (aka "shopping list"). We have gone barking mad.
- JoeAltmaier 9y agoHa, your cell phone is sort of like that. All that to replace, just waiting until you get home to make the call. To be fair, this 3D trick also replaces remembering, driving, buying, restocking.
- icebraining 9y agodriving, buying, restocking How so? You can already order online. All this devices replaces is the clicks it takes to do that. A cellphone means you don't have to choose between receiving calls or going out. It's incomparable in its utility.
- PascLeRasc 9y agoUgh, just like all those trillions of man-hours spent making cars just to replace some simple horses. What a world we live in!
- drb91 9y agoWell, horses are more renewable than petrol.... personally I think the jury’s still out on that one. Just because people call it progress doesn’t mean the world is a better place.
- TeMPOraL 9y agoInternal combustion engines are more important than just cars. They enabled powered flight. They enabled heavy construction and mining machinery. They enabled plenty of other high-impact things in our lives. And at the very least, they don't stink as much - towns eventually drowning in horse manure was a real fear in the times just before the first automobile. That said, we're now on the verge of switching most of ICE uses into electricity, which can be made more renewable than horses. We'll be good, if we can make the transition.
- TeMPOraL 9y agoReplacing shopping list was but one of the use cases given. I agree it's a ridiculous one, but there's plenty of actually useful applications for things interacting with RF that can be mass-produced cheaply.
- jstanley 9y agoThe antenna is made of a conductive plastic.
- stephengillie 9y agoFrom the article: > In this case, the antenna is contained in a 3-D printed object made of conductive printing filament that mixes plastic with copper. So this appears to be some sort of copper-plastic alloy that prints well and is conductive after printing. This part seems more revolutionary than the commercial aspect.
- TeMPOraL 9y agoExactly. And when they say "Wi-Fi", they mean "2.4GHz signals". Wi-Fi is a protocol, and "connection" means bidirectional communication, which is not happening here. I try to not nitpick too often, but things like this really irk me. And before someone says that it's a simplification for non-specialists - this is exactly the problem. Such stupid "simplifications" only serve to confuse people, instead of educating them. They promote fairy tales (easy to exploit later) instead of building an accurate model of reality. Writing things like that is wrong, and hurtful to the readers. Writing things like that intentionally is simply malicious.
- sctb 9y agoOK, we've updated the headline by omitting words from this phrase from the article, “...3-D printing plastic objects and sensors that can collect useful data and communicate with other WiFi-connected devices...”.
- leoedin 9y agoThe article is incredibly light on detail. Making 3D printed items with switches in them is really easy. It's the receiver that's the hard part. It would be great if they actually gave details. I want to know: 1. What device is receiving the signals. Is it commodity hardware (like a phone or laptop) or do they have to build a custom RF receive chain? 2. What software is used? What signal processing do they have to do? How does the software differentiate between one device and another one? The interesting, ground breaking stuff is all in the electronics and software. The 3D printing stuff is fluff - it's just taking 100 year old technology and adding "3D printed" to it to make it seem modern.
- jldugger 9y agoCitations are always a researcher's best friend. The video has a URL researchers, http://printedwifi.cs.washington.edu/ http://printedwifi.cs.washington.edu/. That page has a paper PDF, with the following line: > We note that prior electronic-based designs use both Wi-Fi signal variations (RSSI) as well as channel state information (CSI) variations [Kellogg et al.2014] to extract backscatter data. The backscattered signal from our 3D printed objects can be extracted using either of these procedures. Our implementation uses the MAX2829 802.11a/b/g transceiver that gives us access to the received 802.11g baseband signal. Based on my time in grad school, I'm guessing they custom built a microcontroller for the task, and used that chip. There's a wealth of papers online dealing with backscatter, including the Kellogg paper cited above. Among their proposed setups is this fairly passive one: > Finally, we check the feasibility of using only the periodic beacon messages from the AP. We use an Intel Wi-Fi Link 5300 card configured as the AP and an Intel Wi-Fi Link 5300 card as a Wi-Fi reader. The reader does not generate any traffic on the network and passively listens to the beacon messages periodically transmitted by the access point. No other device is associated with the access point, but it operates on channel 6, which is the same frequency as our organization’s Wi-Fi network. Your other questions may be similar answered by following citations =)
- smarx007 9y agoDetails from the paper itself [1]: - uses MAX2829 802.11a/b/g transceiver - if WiFi preamble is detected, pass it further up the stack - otherwise normalise the signal and apply apply a 10th order 100 Hz low pass filter. - bitrate is 45bps :) [1]: http://printedwifi.cs.washington.edu/printedwifi.pdf http://printedwifi.cs.washington.edu/printedwifi.pdf
- stephengillie 9y agoImagine a WiFi prism, where "light" (RF) waves are refracted into a specific pattern, separating channels into bands across a room.