Princeton Grinding Imaging and Reconstruction Instrument (GIRI)
Construction on the new NSF-supported, Princeton University lab facility dedicated to the digital reconstruction of hidden objects through serial grinding and imaging has been completed. The purpose of a destructive technique like serial grinding is to facilitate the discovery of embedded objects with weak density contrasts outside the sensitivity limits of X-ray CT-scanning devices. The device we have developed is a retrofit imaging station designed for a precision CNC surface. The instrument is capable of processing a sample 20x30x20 cm in size and accurately (to 0.25 micron) stepping at 2.5 micron resolution in x, y and z axes. Directly coupled to the vertical axis of the grinder is an 80 megapixel medium format camera and specialty macro lens capable of imaging a 12x12 cm surface at 5 micron resolution in full 16 bit color. The system is automated such that after each surface grind, the sample is cleaned, travels to the opposite end of the bed from the grinder wheel, is photographed, and then moved back to the grinding position. This process establishes a comprehensive archive of the specimen that is used for digital reconstruction and quantitative analysis. In one night, a 16 cm thick sample can be imaged completely at 20 micron horizontal and vertical resolution without human supervision. Some of the initial projects we have in the queue include the digital reconstructions of early animal fossils, 3D sedimentary bedforms, the size and shape distribution of chondrules in chondrites, and the porosity structure of carbonate reservoir rocks before and after carbon sequestration and carbonate diagenesis experiments.
This lab is a collaboration between Adam Maloof and Situ Studio. We currently are looking for a postdoc and graduate students to work on grinder related projects.