Images 2016

Best image:

"Day of tentacles", Thomas Lettner, QNP/APHYS

Day of tentacles: The image seems to show some strange alien life form equipped with long, semi-transparent tentacles. In fact it was acquired during wet chemical etching of circular shaped microphotonic structures in gallium arsenide. A sample was patterned with a matrix of circles with a diameter of 4 micrometers and a spacing of 20 micrometers by optical lithography. It was then etched using an ammonia and hydrogen peroxide solution. During the etching process some of the etched material must have been redeposited on the sample, thereby forming those long strands with the previously defined circles as their origin. The image was taken with a Nikon Eclipse ME600 microscope and a Moticam 2300 CCD camera with 3 megapixels using a 20x objective. Some general post processing (brightness, contrast and sharpness) was applied to the image afterwards. ( Original image (jpg 1.1 MB) )

Submissions:

Voting statistics: 1 (3 votes), 2 (11), 3 (12), 4 (3), 5 (4), 6 (10), 7 (8), 8 (3)

Prize: Iphone SE

1. Patterned fractals

"Patterned fractals", Jin Dai, OFO/MNF

Patterned fractals: The  microscope image shows the change in morphology of two dimensional periodic gold patch arrays with a period of 4um after annealing in N2 flow at 600 degree celsius for 10 minutes. Each gold patch deforms into an engraved tree-root-like pattern, which most probable also has fractal features.  Each pattern is unique but shares some similarities with the others. This exotic phenomenon has not been observed in thermal annealing of continuous gold thin films. ( original image (jpg 667 kB) )

2. Crystal domain

"Crystal domain", Hoda Kianirad, LaserFysik/APHYS

Crystal domain: The image is taken by differential interference contrast microscopy technique. It illustrates self-assembled domain structure in MgO doped Lithium tantalate crystal after selective etching in HF acid. ( Original image (jpg 403 kB) )

3. Day of tentacles

"Day of tentacles", Thomas Lettner, QNP/APHYS

Day of tentacles: The image seems to show some strange alien life form equipped with long, semi-transparent tentacles. In fact it was acquired during wet chemical etching of circular shaped microphotonic structures in gallium arsenide. A sample was patterned with a matrix of circles with a diameter of 4 micrometers and a spacing of 20 micrometers by optical lithography. It was then etched using an ammonia and hydrogen peroxide solution. During the etching process some of the etched material must have been redeposited on the sample, thereby forming those long strands with the previously defined circles as their origin. The image was taken with a Nikon Eclipse ME600 microscope and a Moticam 2300 CCD camera with 3 megapixels using a 20x objective. Some general post processing (brightness, contrast and sharpness) was applied to the image afterwards. ( Original image (jpg 1.1 MB) )

4.  Lighting up a dark Swedish lab

"Lighting up a dark Swedish lab", Federico Pevere, Nano-Si/MNF

Lighting up a dark Swedish lab: It is getting dark here in Sweden while we approach winter times. Apart from taking vitamin D, I thought to brighten our photoluminescence laboratory at KTH by using our “Silicon nanocrystals candles” (which you don’t find in IKEA yet). Here you can see a photo taken by a digital camera with an UV flash while “lighting” the right candle. The “flame” of the left candle is made by Silicon nanocrystals (approximately 3 nanometers in diameter) embedded in a polymer matrix which emit reddish light thanks to the quantum confinement effect. The latter is responsible also for the orange emission by porous Silicon particles contained in the plastic vial which is lighting the candle on the right. Our research is focused on the luminescence properties of Silicon nanocrystals which could lead in the future to low-cost environment-friendly phosphors for biomedical, photovoltaic and optoelectronic applications. ( original image (jpg 3.6 MB) )

5. Structured anti-reflection metal-oxide layers

"Structured anti-reflection metal-oxide layers", Dennis Visser, HMA/MNF

 The image shows the fabrication of a structured metal-oxide layer/periodic structure for the implementation in optoelectronic devices in order to decrease surface reflections. A molding technique has been applied, possible by a Smart Force infilling technique or by a drop-cast/vacuum method. A polydimethylsiloxane (PDMS) mold has been created by using pre-structured micro-cone structure (consisting of hexagonally ordered cones with a period of 3.5 μm, a height of 1.5 μm, a lower diameter of 3 μm and a top diameter of 0.5 μm), shaping the PDMS on this and followed by a peel-off. A structured metal-oxide structure, based on nanoparticles, can be obtained by infilling of the PDMS mold by a controlled solution based drying process. By optimizing the mold for the desired periodical and dimensional parameters and optimizing the metal-oxide infilling, a structured metal-oxide layer/periodic structure can be obtained that can be implemented on surfaces of optoelectronic devices for anti-reflection purposes. 
IMAGE: In the left part of the image the PDMS mold, containing the hole structures, is shown and on the right side the structured metal oxide layer/periodic structure is shown. The inset shows the (distribution of) metal oxide nanoparticles on which the metal-oxide structures are based. ( original image (png 425 kB) )

6. Pine pollen

"Pine pollen", Miao Zhang, Nano-Si/MNF

Pine pollen: An unexpected pollen from a pine tree was spotted on a wafer in SEM. Colorization of the image was done by GIMP. ( original image (png 2.5 MB) )

7. Luminescent transparent wood

"Luminescent transparent wood", Ilya Sytjugov, Nano-Si/MNF

 Luminescent transparent wood: Three pieces of transparent wood, impregnated with quantum dots of different sizes, floating on water. Luminescent colors vary under UV-lamp illumination due to quantum size effect. Real colors.

8. Simply a line

"Simply a line", M. Yan, OFO/MNF

Simply a line: Image shows a hair-thin line printed by a laser-jet printer (Konica Minolta) on a normal A4 paper observed under a microscope (magnification 2000x). Different from calligraphy, the printer uses micrometer-sized dots (most likely carbon-polymer mixture) to create the line. With the same-sized dots, the printer can print complex gray-scale photos. One also from the image can see how microstructured a paper surface is. Micro- and nanotechnologies have modernized our lives, ages ago, without we realizing it.

Page responsible:Max Yan
Belongs to: School of Engineering Sciences (SCI)
Last changed: Oct 20, 2016