MIT scientists create a system to change the colors of objects

A new way to change the colors of objects was developed by a team of scientists from the Computer Science and Artificial Intelligence Laboratory (CSAIL) at MIT.

Researchers have developed a method based on a programmable ink that allows a surface to change color when exposed to ultraviolet light or visible light rays at certain wavelengths. The system, called PhotoChromeleon, uses a certain ink made from liquid photochromatic dyes that can be sprayed or even painted. Once applied, the object can change color or colors depending on the light beam that illuminates it, a reversible process that can be repeated.

The system has already been tested on different types of objects, from smartphone cases to model cars, and the same researchers have created a video that has been published on YouTube.

And it is precisely in the area of personalization that such a system could find its best application, as Yuhua Jin, the main author of the study related to this project implies: “Users can personalize their personal effects and appearance on a daily basis, without having to buy the same object several times in different colors and styles.”

The researcher, together with his colleagues, adapted an already existing system called ColorMod, which however had to print every pixel on the object. Furthermore, the colors can only be two: the basic color of the object or transparent. This new method allows you to change all the desired colors, depending on the photochromic dye that is applied to the surface.

Each dye interacts with different wavelengths and therefore it is possible to control each “color channel” of the color, depending on the wavelength of the emitted light source, to activate or deactivate it as desired. The method involves placing the object in a box with a particular projector and an ultraviolet light that serves to “erase” the colors and start again.

The same researcher also thought of creating an interface for automatic processing of drawings and models, offering users a kind of autonomy for personalization. The coloring process takes 15 to 40 minutes, depending on the shape and size of the object.


See also:

https://www.csail.mit.edu/news/objects-can-now-change-colors-chameleon

https://hcie.csail.mit.edu/research/photochromeleon/photochromeleon.html

Image source:

http://news.mit.edu/sites/mit.edu.newsoffice/files/images/4%20color-changing%20shoes.png

Sound and light waves can be used in silicon chips for more efficient computers

A new step in the context of increasingly efficient silicon-based computers seems to have been taken by researcher Avi Zadok of the Faculty of Engineering Sciences at Bar-Ilan University. One of the biggest problems with modern computers whose functions have been extended to include photonics is that optical signals, like electrical signals, move too fast.

Sometimes slower motion may be better, as explained in the press release: “Important signal processing activities, such as accurate selection of frequency channels, require data to be delayed at timescales of tens of nano-seconds. Given the high speed of light, optical waves spread over many meters at these time intervals. It is not possible to accept these path lengths in a silicon chip. It is not realistic. In this race, fasting does not necessarily win.”

One way of overcoming a similar problem is to use acoustic waves: the signal in question can be converted from the electrical domain into an acoustic wave. Because the speed of sound is lower, the new converted signal can have the necessary delay at tens of micrometers instead of meters. After propagation, the same delayed signal can then be converted back into an electrical signal.

This is what Zadok is trying to do with photonic computers, especially a system that combines light and sound in standard silicon, even if the same concept can be applied to any type of substrate, not just silicon.

Zadok himself adds in the press release: “Acoustics is a missing dimension in silicon chips because the acoustics can perform specific tasks that are difficult to perform only with electronics and optics. For the first time, we have added this dimension to the standard silicon photonics platform. The concept combines the communication and bandwidth of light with the selective processing of sound waves.”

This progress can be useful in applications related to 5G.


See also:

https://www.nature.com/articles/s41467-019-12157-x

Image source:

https://assets.newatlas.com/dims4/default/b45f372/2147483647/strip/true/crop/464×310+0+136/resize/1160×774!/quality/90/?url=https%3A%2F%2Fassets.newatlas.com%2Farchive%2Fsound-amplified-light-1.jpg

Small 2 nanometer gas detector made by Japanese researchers

A gas detector inspired by the signals received by living cells was designed by a research group at the University of Tokyo. The detector is based on a cube, defined as a nanocube, the size of one-fortieth of a human red blood cell, with only two nanometers for each side. This nanocube can shine if it detects LPG gas.

The team has been working on this project for more than ten years, during which time researchers have tried to mimic the ways in which proteins and DNA unite in living cells. “People automatically think of devices when we talk about sensors. But there are many examples of natural sensors in the body,” explains one of the researchers involved in the project, Shuichi Hiraoka, head of the Department of Science at the Japanese university.

A cell, in order to detect the signals, usually operates in three phases: in the first, a receptor detects the target molecule, in the second a detector sends a signal and in the third, the detector sends the signal to another place in the cell.

The nanocube simplifies this system because it is both the receptor and the restorer. By doing this, as Hiraoka himself indicates, one can avoid the problem of transferring information from the receiver to the receiver. In nanocubes, they glow blue with ultraviolet light when they are filled with LPG.

These sensors can wrap the molecules they contain and can detect even very small amounts of LPG gas. They are very specific to this type of gas, something that other traditional gas detectors cannot afford. Currently, researchers are working on detecting different gases on the device.


See also:

https://www.u-tokyo.ac.jp/focus/en/press/z0508_00070.html

https://www.nature.com/articles/s42004-019-0212-6

Image source:

https://www.u-tokyo.ac.jp/content/400122539.jpg