Ultra-portable, wireless smartphone spectrometer for rapid, non-destructive testing of fruit ripeness.
We demonstrate a smartphone based spectrometer design that is standalone and supported on a wireless platform. The device is inherently low-cost and the power consumption is minimal making it portable to carry out a range of studies in the field. All essential components of the device like the light source, spectrometer, filters, microcontroller and wireless circuits have been assembled in a housing of dimensions 88 mm × 37 mm × 22 mm and the entire device weighs 48 g. The resolution of the spectrometer is 15 nm, delivering accurate and repeatable measurements. The device has a dedicated app interface on the smartphone to communicate, receive, plot and analyze spectral data. The performance of the smartphone spectrometer is comparable to existing bench-top spectrometers in terms of stability and wavelength resolution. Validations of the device were carried out by demonstrating non-destructive ripeness testing in fruit samples. Ultra-Violet (UV) fluorescence from Chlorophyll present in the skin was measured across various apple varieties during the ripening process and correlated with destructive firmness tests. A satisfactory agreement was observed between ripeness and fluorescence signals. This demonstration is a step towards possible consumer, bio-sensing and diagnostic applications that can be carried out in a rapid manner.
MIT Media Lab, Massachusetts Institute of Technology, 75 Amherst, St. Cambridge, MA, 02139, USA.
Anshuman J
AJ
Das
WeSchool, Lakhamsi Nappu Road, Matunga East, Mumbai, Maharashtra 400019, India.
Akshat
A
Wahi
VIT, Near Katpadi Rd, Vellore, Tamil Nadu 632014, India.
Ishan
I
Kothari
MIT Media Lab, Massachusetts Institute of Technology, 75 Amherst, St. Cambridge, MA, 02139, USA.
Ramesh
R
Raskar
D002734:Chlorophyll / Q000032:analysis*; D034201:Computers, Handheld; D005504:Food Analysis / Q000295:instrumentation* / Q000379:methods; D005638:Fruit / Q000254:growth & development / Q000378:metabolism*; D006801:Humans; D027845:Malus / Q000254:growth & development / Q000378:metabolism; D061848:Optical Imaging / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D063245:Plant Development / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000191:economics / Q000295:instrumentation / Q000379:methods*
D002734:Chlorophyll