UNS – A chemistry learning tool developed by students of Universitas Sebelas Maret (UNS) Surakarta has successfully advanced to the 2024 National Scientific Week (Pimnas). This tool, named LocoPoco, stands for Low-Cost and Portable Colorimeter. With low production costs, practical use, and accurate results, LocoPoco stands out as an innovative solution.
LocoPoco was developed by five students from the Chemistry Education Program in the Faculty of Teacher Training and Education (FKIP) at UNS. The team, led by Yoga Prasetyo Pamungkas, includes Armatevia Patricia, Mayliana Ariyani, Agnes Sabila, and Ainun Jariyah. Their advisor, Dr. Ari Syahidul Shidiq, S.Pd., M.Pd., guided the team through the UNS Student Creativity Program (PKM) Karsa Cipta (KC).
The idea for LocoPoco originated from the challenges faced by high school students in understanding chemistry material. The lack of laboratory tools and the high cost of available equipment were significant barriers. LocoPoco was created to improve students’ understanding of chemistry by providing a practical way to engage with the subject.
Yoga explained to uns.ac.id that LocoPoco serves as a learning tool for stoichiometry experiments, making abstract concepts more tangible. Stoichiometry, often challenging for students due to its focus on chemical calculations and measurements, can now be taught more effectively using this tool, bridging the gap between theoretical formulas and practical application.
“The abstract nature of stoichiometry often leads students to rely on memorization to overcome difficulties. Using this tool in practical applications helps students understand stoichiometry down to the submicroscopic level and its real-world uses,” Yoga said on Monday (16/9/2024).
The device operates similarly to a spectrophotometer, applying Lambert-Beer’s law to measure the absorbance of a sample by passing light of a specific wavelength through it. The absorbance value and the resulting calibration curve determine the concentration of the sample.
LocoPoco is designed to measure the concentration of solutions by capturing light from Red, Green, and Blue (RGB) Light Emitting Diodes (LEDs) with a Light Dependent Resistor (LDR) sensor. The response is processed by an Arduino Uno R3 and transmitted to a smartphone via Bluetooth, displaying the sample’s concentration and the calibration curve on a spectrophotometer detector app.
What makes LocoPoco exceptional is its low cost, portability, accuracy, and simple design. These features make it a highly suitable tool for educational purposes, aiding teachers in conducting stoichiometry experiments and helping students understand chemistry through submicroscopic approaches by calculating solution concentrations. The UNS student team has already introduced LocoPoco to students at CT ARSA Foundation Sukoharjo High School, where they conducted independent experiments to determine the concentration of naphthol in batik waste from Solo Raya using the tool.
“The production cost of LocoPoco is approximately 8 million rupiah, whereas a commercial spectrophotometer costs around 250 million rupiah. Thus, our simple colorimeter is affordable, portable, and as effective as conventional spectrophotometers,” Yoga explained.
The chemical analysis method using a simple colorimeter like LocoPoco has broad applications. In the food industry, it can measure the concentration of food and beverage coloring. In environmental studies, it can assess the levels of colored pollutants in the surrounding environment. In education, colorimetry techniques can be used in simple lab experiments to teach spectrophotometry principles.
UNS students’ participation in the 37th Pimnas provides an excellent opportunity to contribute to the achievement of Key Performance Indicator (KPI) 2. Success in a national competition like Pimnas demonstrates students’ involvement in extracurricular activities, which aligns with KPI 2—gaining experience beyond the campus. Pimnas also serves as a platform for students to present the results of their PKM projects and exchange ideas through intellectual products on a national scale. The UNS PKM KC team is currently preparing an indexed scientific article for SINTA 2, presentation materials and posters, and conducting further tests on the effectiveness of LocoPoco in various high schools.
“We have conducted effectiveness trial tests at SMA Negeri 3 Surakarta and SMA Negeri 1 Ngemplak, following successful tests at CT ARSA Foundation Sukoharjo High School. The trials yielded positive data, helping us prepare for the upcoming Pimnas 37,” Yoga concluded.
Humas UNS
Reporter: R. P. Adji
Editor: Dwi Hastuti
