Tonight, Google will announce the winners of its fourth annual Google Science Fair, which Scientific American co-sponsors. Watch the awards ceremony here live.

The 15 global finalists, ages 13 to 18, set up their projects yesterday at Google headquarters in Mountain View California for judges and members of the public to see. The grand prize winner will receive a $50,000 scholarship, a 10-day trip to the Galapagos Islands, a behind the scenes look at Virgin Galactic’s commercial space program, a $10,000 grant for their school and many other perks. Here are highlights from this year's amazing batch of projects.

The Fruit-Fly-Inspired Flying Robot can dodge incoming objects fast.

Fruit Fly-Inspired Flying Robots: Rotting fruit inspired 14-year old Mihir Garimella of Pittsburgh to design a new navigation system for robots. “Last summer, my family went to India, and when we came back we realized there were these bananas on the counter that we forgot to throw out,” he says. “So our house was filled with fruit flies that I was trying to swat.” To his frustration, he realized how quickly the fruit fly’s visual system operates despite the tiny size of its brain (only 100,000 neurons versus a human’s 100 billion). Using infrared distance sensors, Arduino programming and a quadrotor – a flying robot with four propellers – Garimella designed a mini flying machine that can take off rapidly in response to objects approaching from different directions. The machines, he says, can be deployed to survey disaster zones and would be able to nimbly navigate around obstacles and evade falling debris.

Update: Garimella won his age category and the computer science prize.

Bacteria Vs. World Hunger: A chance observation about warts on a pea plant led three friends from Kinsale, Ireland on a three-year mission to solve the world food crisis. Emer Hickey, Ciara Judge, and Sophie Healy–Thow, all 16, learned that the wart-like nodules hold beneficial bacteria known as rhizobia that produce ammonia and other compounds that help the plants grow. At the time, their class was studying the world food crisis in geography, and an idea for a science project quickly germinated. “We became really interested in what this bacteria can do and what people haven’t done with it so far,” said Healy-Thow.

Though many people told them that the bacteria would have no impact on cereal crops, the friends decided to test it on barley. They found that the microbes increased seed germination rates by 50 percent. Over the course of three years, the team has tested some 13,000 seeds and has a large controlled field site set up with another 3,600 seeds in their hometown. Hickey says the bacteria may also reduce the need for chemical fertilizers, which can harm the environment.

Update: Hickey, Judge, and Healy–Thow won their age category and took home the grand prize.

The olfactory alarm clock can wake you with the scent of mint or money.

Olfactory alarm clock: Why wake up to a jarring beep when you can rise to the scent of peppermint -- or crisp dollar bills? Guillaume Rolland, 17, of Nantes, France, hatched his idea after learning that hearing-impaired patients at a nursing home where his father works needed nurses to wake them each day. He built an alarm clock equipped with a small filter onto which users can drip a variety of scents. He has worked with perfumers to synthesize the smell of coffee, freshly baked bread, chocolate, and, yes, American dollars. When it’s time for the alarm to go off, a small fan at the back of the clock spins, and a tiny door at the top of the clock opens so the fan can blow air through the filter and disseminate it near the sleeper. In pilot tests on nursing home patients, teenagers and adults, Rolland says the menthol scent woke people within 2 minutes 100 percent of the time.

Rethink: Effectively Stopping Cyberbullying. 14-year-old Trisha Prabhu of Naperville, Ill. designed a program that can detect hate speech and make a teenager think twice before using it. At the science fair she demonstrated the software by typing “You are so ugly @jilljone,” into a Twitter like interface. A message immediately popped up warning that the note could be hurtful and asking if she was sure she wanted to post it. It then gave the option of editing the message or posting it anyway. Rethink also notifies parents about bullying comments their child may post online.

Dilbagi plotted dots and dashes onto the letters of the alphabet to help users learn Morse code.

TALK – a communication system for people with disabilities: Arsh Shah Dilbagi of Panipat, India came up with a way to convert long and short breaths into Morse code that a computer can then translate into speech. He then designed a creative way to teach people Morse code, by plotting dots and dashes onto the letters of the alphabet. He says his device, which cost less than $100 to make, is cheaper and faster than current technology.

Update: Dilbagi won the Voters Choice Award.

TheraNIM: A Touchless Respiratory Monitor. Eswar Anandapadmanaban, 16, from Jersey City, NJ was inspired by the ghostly instrument the Theramin – used to create creepy sound effects in science fiction films -- to design a less invasive and inexpensive way for caregivers to monitor patients’ breathing. Like the Theramin, the TheraNIM is touchless. It monitors breathing by creating an electrical field around a patient and detecting the chest movements that accompany inhalations and exhalations. One of its advantages, says Anandapadmanaban, is that it keeps patients comfortable because it requires no stick-on electrodes or other wires and sensors.

Drobnych built a microscope from a LEGO Mindstorms kit

Remote-controlled school presentation microscope: Mark Drobnych, 13, of Uzhgorod, Ukraine used a LEGO Mindstorms kit to create a microscope with two lenses and four glass slide holders that teachers can use to show students a variety of images on a projection screen. A Web cam enables schools around the world to compare images and results. He came up with the idea after watching his science teacher run between desks as she tried to help each student properly set up his or her experiment. He said his invention can also benefit schools that don't have enough money to supply each child with a microscope.


Image credits: Anna Kuchment