We present a toy-brick based tabletop tensometer for research and education.
The data aquisition PCB was redesigned, now including a 16-bit ADC for force and resistance readings. Updated Eagle Files in the Download section.
Constructing the Testers frame is as simple as building a standard LEGO model.
All building instructions are completely open source and available in the Download section.
Strain, force and Resistance measurement - in one device. The LTT is designed to characterize soft materials and stretchable conductors both mechanically and electrically via stress-strain and resistance-strain measurements.
Sample strain is measured by tracking the movement of one clamp via a commercial digital caliper with an overall accuracy of 100 um.
Tensile force is measured with a 3rd party vendor LEGO Mindstorms force gauge (Vernier Inc.), enabling 10 N and 30 N measurement ranges with accuracies of 30 mN and 150 mN respectively.
Resistance is measured by passing a defined current through the speciment and reading the voltage drop across it. Six measurement ranges assure a accuracy of 0.1% of each measurement range.