Jun 26, 2012
Chemical classification is an important operation for many industries. Typically, this is done with portable spectrometers that cost on the order of $5000. The data from portable spectrometers must be transported back to the lab to have post processing determine what the contents of the measurement were. The complexity of these spectrometers is often excessive; the expensive scientific grade accuracy instruments are useful for separating every single chemical known to man, but in the cases where only two classes are needed (clean air vs. anthrax in air), a wider network of less expensive instruments programmed specifically for this detection task will be more suitable.
Smartphones natively contain almost all of the components required for spectroscopic material distinction, and many companies provide their employees with these devices. The smartphone comes equipped with a camera, a processor for image analysis, and a display for an immediate visual feedback. The only component missing is a diffractive element that will separate the light beam into spectral components.
Our Hand-Held Hadamard Spectrometer (H3S) device is a small portable spectrometer that attaches to the camera of smart phones. Our design consists of three components, a spectrometer that mounts onto a smartphone camera, a smartphone application that performs the required data processing on the data that is acquired by the smartphone, and an initial calibration of the application for each specific task by professionals familiar with the classification task. We will use a Hadamard mask in the design instead of the traditional slit to increase our signal to noise ratio. The use of the Hadamard mask will require some post processing of the measurement, but the smart phone comes with the required processing power. The attached optics will be plastic aspheric lenses and grating inside of a housing designed to attach to a smartphone. The device is quick, efficient, and performs no more measurements or calculations than necessary to distinguish between samples.
The H3S can be used in a variety of applications. These include mining or drilling companies who use this device in initial surveys of earth; military applications where periodic tests of the air are required to assure the atmosphere is not contaminated with poisonous gas, or in field tests for potable water.
The H3S device will allow a simple, portable solution to the applications listed above. Large, bulky spectrometers can be left in the lab to perform precise scientific calibrations, while our portable device can be deployed as a large network and will utilize calibrations in the field with instantaneous feedback. The simple nature of the optics allows for scalable manufacturing using plastic injection molding.
This cost of the H3S will be negligible compared to standard high end spectroscopic methods. Portable field ready spectrometers cost on the order of $5000, while the manufacture of our device will cost less than $100.
The H3S is a new, inexpensive device capable of sensitive spectroscopic classification in the field using only a smartphone, analysis application and spectral add on.