Page 8
www.us-tech.com
Self-Assembling Electronics
Continued from page 1
bandgap for semiconductor mate- rials and to make the materials responsive to light - meaning this technique can be used to create optoelectronic devices. “What’s more, current man-
ufacturing techniques have low yield, meaning they produce a relatively large number of faulty chips that can’t be used. Our ap- proach is high yield — meaning you get more consistent produc- tion of arrays and less waste.”
D-Met Reaction Thuo calls the new, self-as-
Tired of seeing red on YOUR pick and place line?
Professor Splice can teach you how to splice with the first < 15 second, 100% reliable splice on the market, and get your company back in the green!
www.smartsplice.com
info@smartsplice.com 717-314-9297
sembling technique a directed metal-ligand (D-Met) reaction. You start with liquid metal par- ticles. For their proof-of-concept work, the researchers used Field’s metal, which is an alloy of indium, bismuth and tin. The liquid metal particles are placed next to a mold, which can be made to any size or pattern. A solution is then poured onto the liquid metal. The solution con- tains molecules called ligands that are made up of carbon and oxygen.
These ligands harvest ions
from the surface of the liquid metal and hold those ions in a specific geometric pattern. The solution flows across the liquid metal particles and is drawn in- to the mold. As the solution flows into
the mold, the ion-bearing lig- ands begin assembling them- selves into more complex, three- dimensional structures. Mean- while, the liquid part of the solu- tion begins to evaporate, which serves to pack the complex structures closer and closer to- gether into an array. “Without the mold, these
structures can form somewhat chaotic patterns,” Thuo says. “But because the solution is con- strained by the mold, the struc- tures form in predictable, sym- metrical arrays.” Once a structure has reached
the desired size, the mold is re- moved, and the array is heated. This heat breaks up the ligands, freeing the carbon and oxygen atoms. The metal ions interact with the oxygen to form semicon- ductor metal oxides, while the car- bon atoms form graphene sheets. These ingredients assemble them- selves into a well-ordered struc- ture consisting of semiconductor metal oxide molecules wrapped in graphene sheets. The researchers used this technique to create nanoscale and microscale transis- tors and diodes. “The graphene sheets can be
used to tune the bandgap of the semiconductors, making the semiconductor more or less re- sponsive, depending on the qual- ity of the graphene,” says Julia Chang, first author of the paper and a postdoctoral researcher at NC State. In addition, because the re-
searchers used bismuth in the proof-of-concept work, they were able to make structures that are photo-responsive. This allows the researchers to manipulate the properties of the semiconduc- tors using light. “The nature of the D-Met
technique means you can make these materials on a large scale - you’re only limited by the size of the mold you use,” Thuo says. “You can also control the semi- conductor structures by manipu- lating the type of liquid used in the solution, the dimensions of the mold, and the rate of evapo- ration for the solution. “In short, we’ve shown that
we can self-assemble highly structured, highly tunable elec- tronic materials for use in func- tional electronic devices,” Thuo says. “This work demonstrated the creation of transistors and diodes. The next step is to use this technique to make more complex devices, such as three- dimensional chips.” Web:
www.ncsu.edu r
Precision Lasers at the Chip Scale
Continued from page 6
tronic chip fabrication world. The success of this technolo-
gy means that it will be possible to deploy these high-performance, precision, low-cost photonics inte- grated lasers in a variety of situa- tions in and out of the lab, includ- ing quantum experiments, atomic timekeeping and the sensing of the faintest of signals, such as the shifts of gravitational acceleration around the Earth.
“You can put these on satel-
lites to make a gravitational map of the Earth and around the Earth with a certain amount of precision,” Blumenthal says. “You could measure sea level rise, changes in sea ice and earthquakes by sensing the grav- itational fields around the Earth.” The compactness, low- power consumption and light weight is a “perfect fit,” he added, for technology to be de- ployed in space. Web:
www.ucsb.edu r
Jan/Feb 2025
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92
