MANILA -- While most people view LEGO blocks as simple toys, one Ateneo de Manila University undergraduate used these familiar blocks to build a low-cost polarimeter — a device that could make science education more accessible.

Improvised polarimeter, made of LEGO bricks, polarizing film, and affordable electrical components, by a Filipino physics undergraduate. Source: Felicidario and delos Santos, Ateneo de Manila University

“I wanted to create a device that could be used in classrooms to demonstrate fundamental concepts like light polarization and optical activity, without the barrier of cost,” Ryan Joseph Felicidario of Ateneo’s Department of Physics’ Photonics Laboratory, said in an interview.

A polarimeter is a scientific instrument that can infer the chemical purity of a substance by measuring the direction in which it rotates polarized light. Polarimeters are used across various industries, including food, pharmaceuticals, chemicals, and biomedical engineering.

Laboratory polarimeters are typically expensive, with commercial manual models priced around P70,000 and high-end versions exceeding P600,000.

According to a press release from his university, Felicidario’s model costs just over P8,000 and is built using only LEGO bricks, polarizing film, and affordable electrical components.

The Applied Physics student shared that he is deeply passionate about science education and his goal has always been to support it. His non-black box model allows people to see exactly how the device functions which makes it a great instrument in class experiments.

“This, I think, is very valuable in education, where understanding the process is just as important as the result,” according to Felicidario.

“Personally, constructing a polarimeter struck my interest because of its interdisciplinary nature — it connects concepts in physics and organic chemistry,” he added.

Felicidario’s model was adapted and modified from the design of Norwegian researchers Lise Kvittingen and Birte Johanne Sjursnes, who also incorporated LEGO blocks. LEGO blocks are modular, accurate, versatile, and easily accessible, making them an ideal choice for the project.

“Since LEGO blocks are familiar to most people, using them makes the project more relatable and approachable, especially for students or those who may not have access to high-end equipment”, he explained.

Felicidario shared that the project was challenging due to the simplicity of the model. “I knew it would not have the same level of precision as a commercial high-end polarimeter, especially when working with samples like ascorbic acid,” he explained.

Through several modifications, Felicidario and his thesis adviser and co-author, Dr. Ramon delos Santos, improved its accuracy and achieved consistent results. They determined the purity of two pharmaceutical brands of Vitamin C (ascorbic acid) by measuring their optical rotation.

Another challenge was the lack of access to a commercial polarimeter to compare results. To overcome this, they used melting point determination to verify the purity of the samples.

Melting point determination involves heating a small amount of a substance in a melting point apparatus to record the temperature at which it melts, which also helps assess the substance’s purity.

In their paper, “Measurement of ascorbic acid samples' optical rotation via an improvised polarimeter for purity assessment,” published in Journal of Physics: Conference Series on October 2024, Felicidario and delos Santos found that one brand of Vitamin C was pure, while the other brand showed deviations from theoretical values, suggesting potential impurities.

Felicidario further said that using the device in educational training could be a good prospect to gain approval from teachers and students.

Felicidario then advised aspiring young scientists to stay curious and be resourceful.

“You don’t always need expensive tools or materials to create something valuable or innovative,” he concluded.