The ability to measure force is a critical need in small-scale systems. This invention is a low-cost force sensor that operates over a force range of 0-200 mN, with a sensitivity of 5 V/N and a resolution of 0.8 mN. Key advantages over competing sensors include lower cost, less weight, smaller size and greater resolution. The sensors are manufactured using pop-up manufacturing, a composite lamination fabrication process, wherein linkages pre-machined in the laminate provide the required degrees-of-freedom and fold patterns to facilitate self-assembly into its final 3-dimensional shape. The sensors are batch-fabricated, further driving down production costs. The transduction mechanism relies on the principle of light intensity modulation, which allows the sensor to detect axial forces with mN level resolution. It was developed for biomedical applications, such as minimally-invasive robotic surgery. But it can also be applied to micro robotics, optical and other applications.