1029 science project ideas, from class 1 to college.

What it shows

An ultrasonic sensor sends out a pulse of sound and times its echo to measure distance. When a hand comes close, the Arduino tells a servo motor to lift the lid.

You will need

• An Arduino Uno and USB cable
• An HC-SR04 ultrasonic sensor
• An SG90 servo motor
• A small dustbin
• Jumper wires and a battery pack

What it shows

The robot measures the distance ahead with an ultrasonic sensor. When something is too close, the program stops, turns and looks for a clear path, driving the motors through a motor driver.

You will need

• An Arduino Uno
• An HC-SR04 ultrasonic sensor, with a servo to turn it (optional)
• An L298N motor driver
• A robot chassis with two geared motors and wheels
• A battery pack and a switch

Safety: Use a proper battery holder and never short-circuit lithium cells.

What it shows

IR sensors shine infrared light at the floor: white reflects it and black absorbs it. The controller reads which sensor sees the line and steers the motors to stay on it.

You will need

• An Arduino or a comparator board
• Two or more IR sensor modules
• A motor driver and two geared motors
• A chassis, wheels and a castor
• Black tape on a white sheet for the track

What it shows

A soil moisture sensor gives a reading that changes with the water in the soil. When the soil is dry, the Arduino switches on a small pump until it is moist again.

You will need

• An Arduino Uno
• A soil moisture sensor
• A small low-voltage pump with tubing
• A relay or transistor driver module
• A pot plant and a water container

Safety: Keep the electronics away from water, and use only a low-voltage pump.

What it shows

Two LDRs compare the light on either side of the panel. The microcontroller turns a servo towards the brighter side, so the panel keeps facing the Sun and collects more energy through the day.

You will need

• An Arduino or similar board
• Two or four LDRs with resistors
• Servo motors
• A small solar panel
• A frame and a power supply

What it shows

A Wi-Fi board receives commands from a phone app or web page and switches relays, so lights and fans can be controlled from the phone and on a schedule.

You will need

• A NodeMCU (ESP8266) or ESP32
• A relay module
• Low-voltage DC lamps or a demonstration board
• A power supply
• A phone app or web dashboard

Safety: Build the prototype with low-voltage loads. Any mains wiring must be done by a qualified electrician.

What it shows

IR sensors detect the train before and after the crossing. The controller closes the gate with a servo and sounds a buzzer as a train approaches, and opens it again once the train has passed.

You will need

• An Arduino
• Two IR sensor modules
• A servo motor
• A buzzer and LEDs
• A model track and gate

What it shows

Flame sensors detect the infrared light from a flame. The robot steers towards the strongest reading and switches on a small pump to spray water at it.

You will need

• An Arduino
• Flame sensor modules
• A motor driver, chassis, motors and wheels
• A small pump, tubing and a water tank
• A battery pack

Safety: Test only with a small candle, under adult supervision, with water ready.

What it shows

An accelerometer detects a sudden impact or tilt. The controller reads the location from a GPS module and sends it by SMS through a GSM module to saved numbers.

You will need

• An Arduino or ESP32
• An accelerometer such as the ADXL335 or MPU6050
• A GPS module
• A GSM module and a SIM card
• A power supply suited to the GSM module

What it shows

Each card carries an RFID tag with a unique ID. The reader picks up the ID by radio when the card is held near it, and the controller logs the name and time.

You will need

• An Arduino
• An RC522 RFID reader and cards
• An LCD display, or a computer for the log
• A real-time clock module
• A buzzer and LEDs

What it shows

The resistance of an MQ-series gas sensor changes when LPG or smoke is in the air. The controller reads it and sounds a buzzer above a set level.

You will need

• An MQ-2 or MQ-6 gas sensor module
• An Arduino or a comparator circuit
• A buzzer and an LED
• A power supply

Safety: Test with a short puff of gas from an unlit lighter, with an adult, away from flames. A school model does not replace a certified home gas detector.

What it shows

A phone app sends commands over Bluetooth to an HC-05 module. The Arduino reads them and drives the motors forwards, backwards, left and right through a motor driver.

You will need

• An Arduino Uno
• An HC-05 Bluetooth module
• An L298N motor driver
• A chassis, motors and wheels
• A battery pack and a phone app

What it shows

A motor spinning an unbalanced weight shakes the whole brush. The angled bristles push forward on every shake and slip backward on the return, so the vibration turns into movement in one direction.

You will need

• A cheap plastic scrubbing brush or a large toothbrush head
• A 3 V DC toy motor
• A blob of hot glue or a small bead and tape for the off-centre weight
• A 2 x AA battery holder with a switch and cells (3 V)
• Double-sided tape or hot glue
• Two pieces of wire

Safety: An adult must handle the hot glue gun. Keep fingers away from the spinning shaft.

Take it further: Build a second bristlebot and race them, changing the weight and bristle angle to see which design wins.

What it shows

An unbalanced motor on a plastic cup makes it wobble on three marker legs, and the wobble is traced out as a looping drawing. The pattern depends on the weight, the speed and how far apart the legs are.

You will need

• A plastic cup or an empty yogurt tub
• Three sketch pens or markers
• A 3 V DC toy motor with a glue blob or a cork piece fixed off centre on the shaft
• A 2 x AA battery holder with a switch and cells (3 V)
• Rubber bands and tape
• A large sheet of paper

Safety: An adult must use the hot glue gun. Keep marker caps and small parts away from toddlers.

Take it further: Add a second motor spinning the opposite way and see whether the drawings become straighter or more tangled.

What it shows

An LDR measures daylight, the Arduino decides open or closed, and an L298N driver runs a geared DC motor in either direction to pull a string curtain across a model window. Two limit switches stop the motor at each end.

You will need

• An Arduino Uno clone and USB cable
• An LDR and a 10 kΩ resistor
• An L298N motor driver module
• A geared DC motor (BO or TT, 3 to 6 V)
• Two micro limit switches
• A cardboard window frame, a cloth curtain, string and a thread spool for the pulley
• A 6 V battery pack (4 AA)

Safety: Battery power only. Keep fingers away from the string and spool while the motor runs. Small parts: keep away from young children.

Take it further: Add a DS3231 clock so the curtain also closes at a set bedtime regardless of light.

What it shows

A rain sensor board has interleaved copper tracks whose resistance drops when water bridges them. The Arduino reads that change and swings a servo to shut a hinged cardboard window, then reopens it when the board dries.

You will need

• An Arduino Uno or Nano clone and USB cable
• A rain drop sensor module with its comparator board
• An SG90 servo
• A cardboard window frame with a hinged flap
• A paper clip and thread for the servo link
• Jumper wires and a 5 V power bank

Safety: Keep water on the sensor board only, away from the Arduino. USB power only.

Take it further: Use the analog value to show rain intensity on three LEDs: light, medium, heavy.

What it shows

An MQ-6 LPG sensor senses a leak and an Arduino rotates a high-torque servo fitted to a model regulator knob to the closed position, sounds a buzzer, and shows the gas level on an LCD. It demonstrates automatic shut-off, not just an alarm.

You will need

• An Arduino Uno clone and USB cable
• An MQ-6 LPG sensor module
• An MG995 or MG90S metal gear servo
• A 16x2 I2C LCD and a buzzer
• A cardboard or bottle model cylinder with a knob the servo can grip
• A separate 5 V 2 A supply for the servo
• Jumper wires

Safety: Test with an unlit lighter only, with an adult present, in a ventilated room. This is a model; never fit it to a real gas cylinder.

Take it further: Add an ESP8266 so the leak event also sends a message to a phone.

What it shows

A PIR sensor detects a bird or animal entering a model field; the Arduino then flaps a shiny ribbon with a servo and plays random beeps for a few seconds. Random timing stops birds getting used to it, a real problem with fixed scarecrows.

You will need

• An Arduino Uno or Nano clone and USB cable
• An HC-SR501 PIR sensor
• An SG90 servo and a strip of shiny foil or old CD
• A buzzer
• A 6 V battery pack (4 AA)
• A stick and a cardboard field with paper crops

Safety: Battery power only. Keep fingers clear of the flapping arm.

Take it further: Add a small solar panel and a rechargeable pack, and log the number of triggers per day.

What it shows

Four LDRs in a cross with small dividing walls sense which side is brighter. Two servos tilt a small solar panel left-right and up-down until all four read the same, so the panel faces the sun. A voltmeter reading from the panel shows the gain over a fixed panel.

You will need

• An Arduino Uno clone and USB cable
• Four LDRs and four 10 kΩ resistors
• Two SG90 servos and a pan-tilt bracket or cardboard frame
• A small 5 V or 6 V solar panel
• A 100 kΩ and 10 kΩ divider to read the panel voltage on A4
• A separate 5 V supply for the servos
• Cardboard for the LDR cross walls

Safety: Battery or USB power only. Do not look at the sun; test with a torch indoors and with the sun only briefly outdoors.

Take it further: Log the panel voltage for both modes all day and plot the energy gain.

What it shows

Instead of light sensors, this tracker computes where the sun is from the date, time and the location, using the real-time clock, and turns a panel to that azimuth and elevation with two servos. It keeps pointing correctly even in cloud, when LDR trackers lose the sun.

You will need

• An Arduino Uno clone and USB cable
• A DS3231 real-time clock module
• Two SG90 or MG90S servos on a pan-tilt frame
• A small solar panel
• A 16x2 I2C LCD
• A separate 5 V supply for the servos
• A phone compass to align the base

Safety: Battery or USB power only. Never look at the sun to check alignment; use the panel shadow instead.

Take it further: Add two LDRs for a fine correction on top of the computed angles, combining both methods.

What it shows

Each light dependent resistor switches the motor on the opposite side, so the buggy turns towards the brighter side and drives at a torch. This is a simple analogue form of phototaxis used in robots.

You will need

• A cardboard or ice-cream-stick chassis
• Two 6 V toy gear motors with wheels and a front castor
• Two LDRs and two 10 kΩ resistors
• Two BC547 transistors and two 1 kΩ resistors
• Two 1N4007 diodes
• A 4 x AA holder with four AA cells (6 V)
• A slide switch, wires, tape and a torch

Safety: Cells only. Keep fingers away from the wheels. Do not let a motor stall for long: a BC547 handles only about 100 mA, so use small motors, or ask an adult to fit a BC337 if the transistors get warm.

Take it further: Reverse the wiring so the buggy runs away from light and hides in the dark.

What it shows

An inverted pendulum falls over unless something keeps correcting it. The robot measures its tilt hundreds of times a second and drives the wheels under the falling body, which is feedback control with a PID algorithm.

You will need

• An Arduino Uno or Nano
• An MPU6050 accelerometer and gyro module
• An L298N motor driver
• Two 6 V to 12 V gear motors with 65 mm wheels
• A two-cell 18650 holder (7.4 V) with protected cells and a switch
• A chassis of acrylic or wood with standoffs
• Jumper wires, nuts and bolts

Safety: Charge the lithium cells only with a proper charger and an adult’s help; never short them. Keep fingers away from the wheels while it balances or falls. Put the robot on a stand while tuning.

Take it further: Add a Bluetooth module so a phone can steer the balancing robot forward, back and in turns.