Fab Lab Instrumentation Reality—From Lab to Field
description
Transcript of Fab Lab Instrumentation Reality—From Lab to Field
Debabrata GoswamiChemistry & Center for Laser TechnologyIIT [email protected]
Current Scientific Instruments are very expensive and highly specialized
Communities that would benefit fromthe use of instrumentation are unable toobtain it
Fab-Labs can be used to design and develop equipment and instrumentation for these communities
Consumer electronics make it possible to develop cheaper instrumentation
Redesigning existing instruments allows lower costs and increased flexibility without lowering performance
UV-Vis Spectrometer
Estimated Cost of $100
RF AnalyzerEstimated Cost
of$100
High Cost, High Sophistication Difficult to use in Field under Rugged environments
UV-Vis Spectrometer: Commercial Cost ≥ $500
Basis of All Linear Absorption Spectroscopy
▪ I=I0exp(-cL) UV-Visible & near-IR
(250 – 1000 nm)▪ Needs scanning of
individual wavelengths▪ Slow▪ S/N Issues
FTIR Measure in Fourier Domain
(perform time-domain measurements) & FT into wavelength domain
I0 I
Spectrum
UV-Vis with consumer electronics Commercially Available UV-Vis
Milk Analysis
Postal Mail
Spectrometry
Remote MedicalAssistance
Distance Learning
Food Quality Analysis Water Quality Analysis
Soil Analysis Agriculture AnalysesMedical Analyses
impulse response(complex frequency
response)DC – MHz~Rs.100
food/water quality, agricultural inputs, ...
580 590 600 610 620 6300.0
0.1
0.2
0.3
0.4 Shaped Pulse Original Pulse
Pho
todi
ode
Sig
nal (
V)
Wavelength (nm)
RF Driving Signal
Undeflected Beam
An Acousto-Optic-Modulator based Pulse Shaper setup with the help an amplified laser system. A couple of representative graphs of the pulse shaping capability is shown in the data that are collected in the wavelength and time-domain respectively.
Laser Pulse In
Shaped Pulse Out
Acousto-Optic Modulator
Schematic
Femtosecond Pulse Shaper
0 200 400 600 800
0
100
200
300
400Fl
uore
scen
ce In
tens
ity (a
rb. u
nit)
Time (sec)
Fluorescence Signal Step function Fit
Speed: Since all of the frequencies are measured simultaneously, most measurements are made in a matter of seconds
Sensitivity: Sensitivity is dramatically improved with FTIR The detectors employed are much more sensitive, the optical
throughput is much higher which results in much lower noise levels, and the fast scans enable the co-addition of several scans in order to reduce the random measurement noise to any desired level
Mechanical Simplicity: The moving mirror in the interferometer is the only continuously moving part in the instrument Very little possibility of mechanical breakdown
Fingerprint Region: Sensitive characterization possible
Micro- and nanoscale prototyping of programmable assembly systems
Theoretical principles for physical computation ("formatics")
Platforms for distributed control of embedded networked devices
Smart tools with feedback control Machines that can make machines Open-source engineering design tools
Visit: http://home.iitk.ac.in/~dgoswami.html
• Prof. Neil Gershenfeld, CBA, MIT• Prof. S.G. Dhande, Director, IITK
Acknowledgements