Author: Juan Aguilar

160 Articles

RepRap Universal Constructor Achieves Self-replication

June 4, 2008 by 14 Comments


RepRap, the self-replicating universal constructor has had our attention since it first started spitting out globs of shapeless goo, but its speculative potential turned in a real benchmark recently when a RepRap machine made parts for an identical machine in a few hours (a child, in other words), then the second RepRap successfully made parts for a third or grandchild machine.

RepRap does not fully assemble copies of itself, but produces the 3D-printed plastic components necessary to assemble another copy. It has also successfully produced other plastic goods like sandals and coat hooks. [Dr. Adrian Bower] is the leader of the RepRap team, and he will be exhibiting its capabilities at this week’s Cheltenham Science Festival.

[via BoingBoing]

ARP Poisoning Is Still A Problem

June 4, 2008 by 5 Comments


You’ve no doubt heard that the site hosting Metasploit, the exploit framework, was hacked earlier this week, but what you may not have heard is that it was done using a layer 2 attack. Though Metasploit.com was not actually cracked, a server on the same VLAN was compromised and used to ARP poison the gateway. ARP poisoning is a method of sniffing data by sending a false ARP message to an Ethernet router to associate the hacker’s MAC address with a valid IP address from a genuine network node. From there the hackers were able to mount their MITM attack and show the image above instead of Metasploit’s website. This problem could have been avoided if the ISP was using fixed ARP entries, which is what [HD Moore] had to do to get the site back online. [Richard Bejtlich] points out that even though most people have been focusing on application security lately, fundamental attacks like this still happen. If you’re doing a good job protecting yourself, you can still be at the mercy of the security of 3rd parties when operating in shared hosting environments.

Hydrophone

June 4, 2008 by 14 Comments


Chances are you’ve never wondered what your goldfish is trying to say, but if you have (or if you just want a project), check out this DIY hydrophone.

You will need a computer microphone, vegetable oil, plastic wrap, scissors, solder, and a small unused plastic bottle. Solder the mic capsule to an appropriate length of cable and test. The entire assembly can then be submerged in vegetable oil inside a plastic bottle. Yes, vegetable oil. Seal the bottle and you’re done.

Playing The Building With David Byrne

June 3, 2008 by 3 Comments


Do you remember the solenoid concert that used a sequencer to control several solenoids striking different surfaces? Musician David Byrne has taken the concept and executed it on a much larger scale with his “Playing the Building” installation in an old municipal ferry terminal in New York. Devices that bang the girders, rattle the rafters, and blow through the pipes of the building are attached to the only object inside, a weathered pipeorgan. Every key is wired to different device in the building, each producing a unique sound. Attendees are invited to fiddle with keys of the organ to produce sounds from the building’s various materials, thus playing the building like an instrument. Here’s a video from the installation.

[via Today and Tomorrow]

Creeping Wave Antenna

June 3, 2008 by 2 Comments


Monitoring medical patients remotely 24 hours a day has always proven to be a difficult proposition due the size of the wireless sensors attached to the patient’s body to relay vital signs. A team from Queen’s University Belfast has come up with a solution that utilizes the creeping wave effect. The effect applies to electromagnetic waves as they come into contact with solid objects. While the majority of the waves are absorbed by the object, a small amount move along the surface of the object before they continue their path.

Since most of the signal sent by conventional biosensors is absorbed by the patient’s body, the signal must be strong enough to compensate. The antennas designed by the Queen’s University team, though, focus their broadcast laterally instead of inward and outward, maximizing the amount of waves that will travel along patients’ bodies via the creeping wave effect and minimizing the amount that are absorbed. These antennas are up to 50 times as efficient as conventional antennas of the same size, broadcasting a stronger signal with less power.

The applications to the wireless body area networking, attaching multiple biosensors to patients’ bodies, field are obvious, but this technology could be used in other ways. Since the creeping wave antenna is small and wearable, it could conceivably be used to boost low power communication to PDAs, cellphones, or any other portable wireless product.

[via Medgadget]

Flying Manta Ray Blimp

June 3, 2008 by 15 Comments

German engineering firm Festo has created this flying manta ray. Dubbed the Air_ray, it’s a balloon made of an aluminum-vaporised “PET foil”. Inflated with helium, the Air_ray’s propulsion system is a flapping wing drive. Each wing has alternating pressure and tension flanks that are attached to an internal set of ribs. The flanks are connected to a remotely controlled servo motor. When pressure is applied to either of the flanks, the wing bends in the opposite direction. By alternating pressure on the flanks, the wings beat. The servos are powered by two 8V LiPo accumulator cells.

The total weight of the Air_ray including the balloon, propulsion system, power supply, and helium is 1.6Kg. Festo has more specs in this PDF.

[via Neatorama]