Introductory physics courses for engineering students often face difficulties in promoting engagement and perceived relevance, particularly when abstract electrical concepts are taught without clear connections to professional practice. This paper reports the design and early evaluation of an innovative challenge-based learning project implemented in a first-year introductory physics course on electricity for biotechnology and chemical engineering students. The intervention was delivered as a five-week intensive multi-instructor course organized into three integrated modules: Physics, Computational Methods, and a Challenge module which included a so-called field instructor to contextualize the project within students¿ professional domains. The course challenge consisted of designing, building, calibrating, and validating a low-cost conductimeter based on a Kohlrausch bridge configuration, reported in the literature, using readily available components. Students applied the instrument to measure the conductivity of fruit and vegetable extracts and to monitor conductivity changes during a chemical reaction, linking physics concepts to applications relevant to biotechnol ogy and chemical engineering. A mixed-methods evaluation was conducted with 34 students using a post-project questionnaire combining Likert-scale items and open-ended questions. Quantitative results indicate high perceived relevance of the project to the Physics module and strong agreement regarding learning new things, with over 77% and 90% of students reporting high to total relevance and agreement, respectively. Importantly, more than 65% of students reported moderate to total perceived connection with their college degrees. Qualitative analysis revealed that circuit construction constituted a major challenge but was also perceived as one of the most rewarding aspects of the experience, suggesting the presence of productive struggle. On the other hand, computational tasks, particularly MATLAB-based analysis, were identified as a significant barrier for some students. All in all, these early findings provide substantial guidance on the challenge project design for future implementation.
