PS 69-123
That’s SLIC! The 1st annual Students Limnology Invention Competition
Students in an upper division Limnology class were taught an engineering design process and then challenged to design and construct a new piece of equipment for winter limnology. Each invention was required to achieve a goal from a list that included: collect water from a specific depth under the ice; collect zooplankton from a specific depth under the ice; measure sechi disk depth under the ice (i.e. fit an 8” disk through a 7” hole), and measure light level at depth under the ice (etc.). Constraints were that the device must work in the winter, be simple enough to use with 10-minute training, be inexpensive (<$50) and be novel. Prototypes were presented to the class with a formal 10-slide presentation demonstrating the invention and the process used, and were judged on a 20pt scale including: Invention works & achieves goal (4pts), Invention meets criteria and constraints (4pts), Invention represents new and creative solution (4pts) etc. The objectives of the Students Limnology Invention Competition were to train students in a structured problem-solving process, to engage students with real challenges in field ecology, and to develope equipment that can be used in investigative environmental science classes in colleges and high schools.
Results/Conclusions
The Students Limnology Invention Competition stimulated excitement and invention attempts by many students. The finalists were inventions to measure light levels under the ice using extensions to hand-held terrestrial light meters, a novel structure for measuring water velocity, and a winter Secchi disk. The winner, the Herdina Collapsible Secchi Disk is a perforated disk, 9” in diameter collapsing to 6” diameter for passage through the ice, painted in black and white quadrants used in limnological studies. It is built from a commercially available food steamer and attachable by clip to a fiberglass measuring tape. Strategically attached wires enable the disk to be lowered into the water, expanded, and then collapsed for retrieval. Total cost to construct: $35.88. The design process included use of design failure mode and effects analysis (FMEA) which resulted in several sequential modifications incorporated into the final design. This device will enable expanded use of experiential ecology lab activities in winter in schools throughout Canada and northern United States and also has the potential to enable expansion to a year-round basis programs such as the Minnesota Citizens Lake Monitoring Program (CLMP).