Showing posts with label Tech-tricks. Show all posts
Showing posts with label Tech-tricks. Show all posts

How to Convert 2-D Patterns Into 3-D Objects Using Only Light ???

Scientists from North Carolina State University have figured out a simple way to convert two-dimensional patterns into three-dimensional (3-D) objects using only light. According to Dr Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State, “This is a novel application of existing materials, and has potential for rapid, high-volume manufacturing processes or packaging applications.” 

Dr Dickey is also the co-author of a paper (“Self-folding of polymer sheets using local light absorption”) which describes the research. 


The process, as researchers describe it, is remarkably simple. Taking a pre-stressed plastic sheet, they run it through a conventional inkjet printer to print bold black lines on the material. The material, then cut into a desired pattern, is placed under an infrared light, such as a heat lamp. 


A news release from the university describes the technique as follows: The bold black lines absorb more energy than the rest of the material, causing the plastic to contract – creating a hinge that folds the sheets into 3-D shapes. This technique can be used to create a variety of objects, such as cubes or pyramids, without ever having to physically touch the material. The technique is compatible with commercial printing techniques, such as screen printing, roll-to-roll printing, and inkjet printing, that are inexpensive and high-throughput but inherently 2-D. By varying the width of the black lines, or hinges, researchers are able to change how far each hinge folds. For example, they can create a hinge that folds 90 degrees for a cube, or a hinge that folds 120 degrees for a pyramid. The wider the hinge, the further it folds. Wider hinges also fold faster, because there is more surface area to absorb energy.

“You can also pattern the lines on either side of the material,” Dickey adds, “which causes the hinges to fold in different directions. This allows you to create more complex structures.” 



Heat Hack – A New Method to Steal ATM Pin Codes


Heat Hack
Heat Hack
A team of UC San Diego security researchers presented a paper on how your Automatic Teller Machine (ATM) pin code can be stolen using the heat that our fingers leave behind. With the help of a digital infrared camera, the person immediately following you can know the keys you pushed, with 80% accuracy.
Frightened? Don’t worry! There are some drawbacks to this method of stealing ATM pins.
Even if the criminal can determine the digits pressed, it is very difficult for him to know the order in which they were pressed. That means he will have to use different combinations of the 4 digits. The second drawback to this ATM pin theft using the heat left behind is that it works only on plastic keypads. This is because if the keypad is made of metal, it gives off too much heat noise that the IR camera cannot distinguish accurately which keys are pressed.
And most of all, a good IR camera that fits this purpose will cost something around $18,000. If one has so much money to get hold of such a costly camera, then I seriously doubt that he will go for stealing ATM pins!
But this does not change the simple truth that our ATM pins are vulnerable to this ‘Heat Hacking’. This type of hacking is not limited to ATM machines, but can be done on keypad safes, security doors, keypad activated garage doors or car doors.
But we can always eliminate the little chance of pin theft by just placing our hand over the entire keypad after entering the ATM pin so that heat is equally given to all the keys in the ATM keypad. This simple step can ruin all the hacking plan of the suspected ‘criminal’ just behind you at the ATM. Do it just as a precaution!

Do let me know your views through your comments.