Stacking the deck: Layers of crystalline nanosheets enable tunable electronic properties

Researchers have obtained and characterized two-dimensional (2D) boron monosulfide (BS) nanosheets. The bandgap energy of a single BS nanosheet was greater than that of the bulk material from which it came. As additional 2D layers were stacked, the bandgap energy eventually decreased to that of the bulk material. This result reflected the tunable electronic properties of BS nanosheets, which are suitable for electronic devices and photocatalytic applications.

Carbon nanotubes could help electronics withstand outer space’s harsh conditions

Space missions, such as NASA's Orion that will take astronauts to Mars, are pushing the limits of human exploration. But during their transit, spacecrafts encounter a continuous stream of damaging cosmic radiation, which can harm or even destroy onboard electronics. To extend future missions, researchers show that transistors and circuits with carbon nanotubes can be configured to maintain their electrical properties and memory after being bombarded by high amounts of radiation.

A new 3D printing frontier: Self-powered wearable devices

Researchers have created an innovative hybrid printing method -- combining multi-material aerosol jet printing and extrusion printing -- that integrates both functional and structural materials into a single streamlined printing platform.

Electrical control over designer quantum materials

In the past few years, suitably engineered stacks of two-dimensional materials have emerged as a powerful platform for studying quantum correlations between electronic states. Physicists now demonstrate how key properties of such systems can be conveniently tuned by changing an applied electrical field.

Stretchy, bendy, flexible LEDs

Engineers have developed a way to print stretchy LEDs on unconventional surfaces using an inkjet printer.

New material could pave the way for better, safer batteries

A material derived from trees could potentially replace liquid electrolytes in next-generation batteries.

Halloween Electronics Project: Jack-O-Lantern

In this Halloween electronics project, I’ll show you how to make a cool Jack-O-Lantern. I used a 3D-printed carved pumpkin, but a real one works just as well (or even better!).

The project is based around three normal LEDs that we control so that they look like a flickering flame. Since my “pumpkin” was very small, I used 3mm LEDs. For bigger pumpkins, I recommend using bigger and brighter LEDs. For example these ultra-bright orange LEDs.

The LEDs are connected in series with a resistor to the PWM pins on the Arduino so that I can control the brightness. And in the code, I change the brightness of each LED to a random value for every 50 milliseconds.

The result? Check out the video below:

Jack-O-Lantern Connection Diagram

Components Needed

• 3 x LED (Orange)
• 3 x Resistor (220 Ω)
• Arduino Uno
• Carved pumpkin (or something else to place the LEDs in)

I 3D-printed this pumpkin model from Thingiverse, but you can place your LEDs in whatever you have at hand. A carved pumpkin? A mummy jar (by wrapping some bandage around a jar and adding eyes)? Or and old /spooky) lantern.

Preparing the LEDs

Start by bending the positive leg (the longest one) of each LED:

Join the three negative legs and solder them:

Solder a resistor to each of the positive legs:

Solder wires for connecting to the Arduino, then cover with shrink tube:

Connect the negative wire to GND on your Arduino and the positive legs to pins 9, 10, and 11 on the Arduino:

Code for Flickering LEDs

The code is pretty straightforward. In the setup() function, I set up the LED pins as outputs. And in the loop() function, I use the analogWrite() function to set a random brightness value to each LED, with a 50-millisecond delay between each change of value.

// Halloween Project: Jack-O-Lantern wit flickering LEDs
// Code by Oyvind Dahl
// www.build-electronic-circuits.com

int ledPin1 = 9;
int ledPin2 = 10;
int ledPin3 = 11;

void setup() {
  // Set LED pins as outputs
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
}

void loop() {
    analogWrite(ledPin1, random(10, 255));
    delay(50);
    analogWrite(ledPin2, random(10, 255));
    delay(50);
    analogWrite(ledPin3, random(10, 255));
    delay(50);
}

Questions about this Jack-O-Lantern project?

Let me know your questions about this Jack-O-Lantern project in the comment section below!

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