Achieving high spatial resolution in contact sensing for robotic manipulation often comes at the price of increased complexity in fabrication and integration. One traditional approach is to fabricate a large number of taxels, each delivering an individual, isolated response to a stimulus. The proposed sensors include a continuous volume of soft material, e.g., a transparent polymer, and light emitting diodes configured to emit light into the transparent volume that can be received by photodetectors. The location and depth of indentations can be measured between all pairs of light emitting diodes and photodetectors in the set, and this rich signal set can contain the information needed to pinpoint contact location with high accuracy using regression algorithms.