Laser category

Electrons Counter-Intuitive Movement

Our ‘common sense’ would say that when an object moves from point A to point B it necessarily has to also move through all the points between A and B. This is, however, not true for electrons in the quantum world, where these intuitive truths are not valid. Electrons can, for example appear on the first floor and then on the third floor – without ever putting a foot down on the second floor (insofar that electrons have feet, of course).

Exactly this counter-intuitive behavior has been observed by professor Hui Zhao and his colleagues in the Ultrafast Laser Lab of the University of Kansas. In the sample, which consists of three different, ultra thin layers, electrons move from the top layer to the bottom layer without ever having been observed in the middle layer. According to Zhao this efficient form of quantum electron transport could play a key role in so-called Van der Waals materials, which have their uses in solar panels and in electronics in general.

The sample that was the subject of the research comprises three layers of semiconductor materials (MoS2, WS2 and MoSe2), each with a thickness of less than 1 nm. These three materials react to light of different wavelengths (colors).

The researchers used a laser pulse with a duration of 100 femtoseconds to knock a few electrons from the topmost MoSe2 layer so that they were able to move freely. With a laser pulse of the correct color for the bottom MoS2 layer (which, thanks to the difference in path length of 0.3mm, arrives one picosecond later than the first pulse), the appearance of the electrons in the bottom layer could be demonstrated. It appeared that the electrons on average needed 1 ps to move from the top layer to the bottom layer.

With a third laser pulse the middle layer was monitored – but no electrons on their way from the top to the bottom were ever observed there. Apparently the electrons ‘jumped over’ the middle layer – a behavior that has also been confirmed through simulations by theoretical physicists at the University of Nebraska-Lincoln.

Source: Elektor

Make Your Own Laser Scanning Microscope

A laser scanning microscope (LSM) is an optical imaging technique for increasing optical resolution and contrast of micrographs. It permits a wide range of qualitative and quantitative measurements on difficult samples, including topography mapping, extended depth of focus, and 3D visualization.

A laser microscope works by shining a beam of light on a subject in an X-Y plane. The intensity of the reflected light is then detected by a photoresistor (LDR) and recorded. When the various points of light are combined, you get an image.

Venkes had built his own DIY laser scanning microscope with a DVD pick-up, an Arduino Uno, a laser, and a LDR. He had also published an A-Z tutorial about making a similar device.

The result image consists of 256×256 pixels with resolution of 200 nm, about 1300 time enlargement, and it will not cost you a lot because you may have most of the parts. However, the scanning process is a bit slow, it may need half an hour for one image, and it is not crispy sharp.

The parts needed for this DIT LSM are:

  • 2 lens/coil parts of a laser pick-up (DVD and/or CD)
  • a bit of PCB
  • a piece if UTP cable (approx 15cm)
  • An Arduino UNO
  • An LDR
  • 2 x 10uF capacitors
  • 1 x 220 Ohm resistor
  • 1 x 10k resistor
  • 1 x 10k pot
  • 1 x 200 Ohm trim potentiometer
  • 1 breadboard
  • 1 switch
  • 1 3,5 mm jack plug
  • 1 audio amplifier
  • 1 laser with a good collimating lens
  • 1 piece of glass, a quarter of a microscope object glass or so to act as a semipermeable mirror
  • The under part of a ballpoint casing to put the LDR in

For the software side, an Arduino sketch is used to steer the lens, to read the LDR values, and to send information to a Processing sketch which will receive the data and translate it into an image.

You can find more details of this project with the source files at the project’s Instructables page. This video shows the device in action:

XPlotter, The All-In-One Plotter, Engraver and Laser Cutter

XPlotter is an affordable and easy to use desktop plotter, Laser cutter and engraver. It is designed to create a new definition of plotter. By integrating the laser engraver and cutter into the mechanism, it becomes a versatile desktop tool for artists, craftsmen and makers to set their imagination free.

The all-in-one machine can simulate real effects of handmade drawing and writing, can cut out and laser engrave on different materials. In addition, it has the capability to pick and place objects perfectly!

This machine is now live on Kickstarter, check out the video campaign to see XPlotter in action:


The writing of XPlotter is outstandingly similar to the real hand writing thanks to the angle of writing and the programmed process. Now you can do your paperwork or write your homework as neat as possible. Also you have the option to choose from a variety of fonts and pens! Drawing outputs also look so real because of demonstrating shadows and tiny tiny details.

A wide range of materials like paper, leather, fabric, cloth, and cardboard are able to be engraved by the laser engraver feature of XPlotter. Short time is needed to engrave your artworks due to the powerful laser equipped with the machine. Safety goggles are included too for making sure that users cope with laser safely.

This personal robot that is dedicated to write, draw and engrave for you has no limits. XPlotter team made a built-in vacuum pump system to enable XPlotter to pick and place at a high speed and features a precision within 0.012mm. It only takes you a few minutes to change the end effector into a vacuum suction cup, which is powerful enough to grab spherical items.

Amazingly, the team behind XPlotter has open-sourced the operation interface to welcome more applications made by users through the secondary development.

In short, these are the specifications of this amazing tool!

Check out this comparison between XPlotter and its alternatives.

The retail price will be around $500 but now you have the chance to get the basic XPlotter via the crowdfunding campaign for only $349. The full kit including engraving and pick and place is priced $529, where the final retail after Kickstarter will be $629. This campaign still has 52 days to go, you can check the campaign page now and choose your reward.

More videos of XPlotter in action can be found at this Youtube profile and the official website.


I finished this laser wall trigger for my HIGH RESOLUTION AND ACCURACY CHRONOGRAPH. The purpose of this device is to generate the trigger start and stop impulses for my chronograph as soon as an object disrupts any of the laser beams.


iKeybo, The Advanced Projection Keyboard

Serafim is a company of some talents and experts in optoelectronics industry, and it aims to offer affordable, useful, and cool consumer electronics for a better computing experience. The latest amazing product by Serafim is: iKeybo!

iKeybo is a virtual projection multilingual keyboard that can turn any flat surface into a keyboard. iKeybo can work as a piano too.

Check this video to see iKeybo in action:

iKeybo uses a non-contact technology and has 90Hz frame rate. It turns your 5 inch display into 12 in a surface since the projection surface is 268*105mm. The keyboard consists of 78 keys where other competitors only have 66. It has a instant reaction around 11.11ms what makes it more convenient while using.You can use iKeybo with you PC, mobile devices and tablets since it works via Bluetooth and USB.

For developers, a SDK for iOS and Android is available! It supports all functions of touch screen which include single tap, double tap, rotate, press and drag, press and hold. Install the framework and make connections with your apps.

It differentiates from other laser projection keyboard because it implements a new patented technology that uses camera sensor and double linear sensors for faster calculation speed and less energy.

“What distinguish iKeybo from traditional projection keyboards is that it is the world’s first laser projection “piano” that allows users to create music instantly with piano, guitar, bass, or drums. When not in use, iKeybo can also serves as an external charger to power up devices with 10 hours of battery life. Its cellphone stand design is also perfect for desk or table to watch movies or start live streaming.“ – iKeybo team

iKeybo Features

4 Language Layouts you can choose from 4 different languages keyboard layouts (English, Spanish, Arabic, and Chinese) to type the language special characters that you need. You can’t add more language layouts to your iKeybo because each layout projection needs a different optical lens. Once you select a language edition or a bilingual one it will be fixed.

4 Musical Instruments with iKeybo you can play piano, guitar, bass and drums! Check this piano demo video:

Round Key Designs a special design to make it easier for typing. Other competitors use square keys with no space in between that make it possible to do a lot of typos.

Portable Charger & Cell Phone Stand  iKeybo also serves as an external charger to power up your devices with 10 hours of battery life. You can also use it as your cellphone stand to turn your mobile device into a computer within just a second.

iKeybo is not the first optoelectronics product by parent company Serafim. Check this page to know more about its products.

iKeybo is now live on a Kickstarter campaign and still has 10 days to go! You can pre-order your iKeybo with one language layout and piano for $89 and also you can get a bilingual iKeybo for $99. More information are available at the campaign page.

Dobot M1, All-in-One Multifunctional Robotic Arm

Shenzhen Yuejiang Technology Co. Ltd (“Yuejiang”) is a leading robot arm solution provider in China. Yuejiang is established in July 2015 in Shenzhen, China by 5 dedicated robotics engineers with the mission of facilitating the development and upgrading of the industrial robotic arms solutions in China and continuously developing the extensive applications in this arena. Yuejiang’s newest product is Dobot M1!

Dobot M1 is an all-in-one industrial robotic arm based on SCARA, with many interchangeable heads to 3D print, laser engrave, solder and pick & place unlimited applications. It also has computer vision ability.

Check this video featuring the amazing capabilities of Dobot M1:

Dobot M1 is the second edition of Dobot 1.0. Dobot 1.0 featured 7 different ways of controlling a robotic arm, including mouse control, vision control, EEG control, mobile APP, Leap motion control and gesture control, that was targeting makers as a new way of personal fabrication. Dobot 1.0 Kickstarter campaign raised an incredible $615,000, shattering a goal of only $36,000, Now Dobot M1 is extending its audience to the education, self-employers and factories sectors providing them an enhanced edition of the multifunctional arm.

Dobot M1 comes to solve the problem that industrial robot arms with such specifications are usually very expensive. Providing Dobot M1 with a price around $2000 will change the manufacturing equation forever. Dobot M1 will be the greatest tool to be added to your working space to try some light manufacturing professionally.

The toolheads included with the arm give multiple choices of operation, whether a 3D printer, gripper hand, laser engraver and 4th axis attachment. Once, it is a 3D printer with 400mm radius and 200mm height printing area itself, and you can extend this printing area with a 1m long trail. Then it is a laser engraver that line engrave and shade engrave your favorite symbols and pictures precisely thanks to the PWM laser it uses.

Attaching it with a camera, you are giving Dobot M1 eyes to process the mission given. It has integrated visual API that can be simply work with OpenCV or your own visual system. It also can be a precise pick and place machine, can do two things at the same time with the dual arm operation feature and can move around!

Dobot M1 support Bluetooth and WiFi, you can connect more than one Dobot together to function simultaneously with the same of multi functions. You can also control them using a mobile app. No need to worry about bein an expert to cope with Dobot M1, you can program it with a visual and easy programming language, and furthermore you can teach it the moves you want it to do with handhold teaching and then it will mimic them. These are the full specification of Dobot M1.

What makes Dobot M1 special is its expandability, it has a standardized head tool port, protocol, API, SDK, and extension ports. It is also considered affordable in comparison with its competitors.

“One simple fact: an industrial SCARA type robotic arm prices between $10,000 and $20,000, two-year payback period. For many small businesses constantly adjusting their production technique, this is too much to afford, not to mention those creative individuals who want a professional making machine. With less than $2,000, and 3 months of payback period, Dobot M1 is here to fill the missing puzzle. With more functions and features, Dobot M1 is able to integrate in more steps of production, helping you save more budget.”

Dobot M1 is now live on a Kickstarter campaign and it only has 3 days to go! Hurry up and pre-order an amazing addition to your fablab or co-working space. You can get the standard kit with two toolheads of your choice with around $1600. It will be a nice automated all-in-one tool for hardware startups that are wasting time and money on different tools and materials doing most of the work by themselves.

For more details about Dobot M1 check the official website and the crowdfunding campaign page.

Constant Current Laser Diode Driver Circuit Using OPA2350 OpAmp

The voltage-controlled current source circuit can be used to drive a constant current into a signal or pump laser diode. This simple linear driver provides a cleaner drive current into a laser diode than switching PWM drivers. The basic circuit is that of a Howland current pump with a current booster (Q1) on the output of a R-R CMOS OPA2350 op amp (U1). Laser diode current is sensed by differentially measuring the voltage drop across a shunt resistor (RSHUNT) in series with the laser diode. The output current is controlled by the input voltage (VIN) that comes from Trim pot PR1.


  • Supply 3,3V DC
  • Load Up to 300mA
  • PR1 Trimpot Current Adjust

Constant Current Laser Diode Driver Circuit Using OPA2350 OpAmp – [Link]


A Laser Treatment To Improve Paper Electronics

NanoEngineers” research group at Iowa University have been devoting efforts to use graphene and its amazing properties in their sensors and other technologies. Graphene has many extraordinary properties. It is about 100 times stronger than the strongest steel. It conducts heat and electricity efficiently and is nearly transparent.

Inspired by some recent projects about using inkjet printers to print multi-layer graphene circuits and electrodes, “NanoEngineers” have been working to move this research further by using the technology for a larger scale flexible, wearable and low-cost electronics. But there was some hurdles in improving the graphene conductivity after being printed and this process may damage the printing surface, such as papers, because of the high temperature or the use of chemicals.

Eventually, these engineers have led development of a laser-treatment process that allows them to use and improve printed graphene for electronic circuits and electrodes, even on paper and other fragile surfaces. The technology is said to show tremendous promise for a wide variety of fields including wearable sensors and thin film transistors with the ability of large-scale manufacturing.

It’s a three step process:

  • Graphene ink formulation: single layer graphene (SLG) powders were mixed with solvents and binders, bath sonicated, probe sonicated, and syringe filtered in order to produce a jettable graphene ink.
  • Inkjet Printing: The resultant graphene ink was syringed into the printer cartridge of a Dimatix Materials Printer and ejected via a piezoelectric nozzle in the subsequent printing process.
  • Laser Annealing:  A pulsed-laser processing of the electrodes using a Nd:Yag laser.
 Formulation, Printing, and Treatment, Source: <a href="!divAbstract">Original Paper</a>
Formulation, Printing, and Treatment, Source: Original Paper

The engineers were able to remove ink binders and reduce graphene oxide by developing a computer-controlled laser technology that selectively irradiates inkjet-printed graphene oxide, Transforming the inkjet-printed graphene into a conductive material capable of being used in new applications is a huge breakthrough in nanotechnology.

More details are available at this paper on NanoScale journal.

Via:  ScienceDaily

Measuring the speed of light with electronics

The speed of light in vacuum is a well-known universal constant and is considered to be the nature’s ultimate speed limit. No matter, energy, and information can travel faster than this speed. The speed of light has always been a topic of great interest and significance throughout history. In the course of measuring the speed of light, scientists have explored numerous ingenious approaches from analyzing the motion of heavenly bodies to artificial quantitative measurements in the laboratory. Michael Gallant describes a very simple approach of measuring this physical constant using an infrared LED, a photodiode circuit, and an oscilloscope. The premise of this method is to allow an infrared beam to travel different distances and then compute the time delay (Δt) between them using the oscilloscope. By measuring the difference in the distances (Δd), the speed of light can be calculated as the ratio of Δd and Δt.

IR Light source
IR Light source

The following diagram describes the setup he used. A Vishay 870 nm IR LED (TSFF5210) generates an IR pulse beam that splits into two beams (L1a and L0) through a beamsplitter (BS). L0 is directly focused onto the photodiode (Pd) using a lens. The L1a beam gets reflected off a mirror, travels along the path L1b, and then focused using a different lens onto the same photodiode. You can see the net path difference between the two beams before they hit the photodiode is (L1a+L1b – L0). If the original IR pulse is kept adequately short, the two optical pulses detected by the photodiode will not overlap in time. An oscilloscope of sufficient bandwidth can therefore reveal the time difference between the two pulses. The photodetector used in this setup was Vishay BPV10 high speed Si pin type with a bandwidth of 200 MHz. The photodiode signal is amplified using an AD8001 Opamp based preamplifier circuit with a gain of 35 (31 dB) and BW of 50 MHz.

Experimental setup for measuring the speed of light
Experimental setup for measuring the speed of light

Michael measured the path difference of the two beams to be 1851 cm and the difference in the time of flight to be 62 nanoseconds from the oscilloscope. This results in the measured speed of light to be 298548387 m/s, which is remarkably accurate for such a simple setup.

Time difference between the arrival of the two pulses can be seen on the oscilloscope
Time difference between the arrival of the two pulses can be seen on the oscilloscope

Find more about this project.