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Description:
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The development of a versatile system capable of providing rapid , portable , and
inexpensive detection of explosives and energetic compounds is needed critically to offer
an enhanced level of protection against current and future threats to homeland security , as
well as to satisfy a wide range of applications in the fields of forensic analysis , emergency
response , and industrial hazards analysis . The hand -held nanocalorimeter will serve as a
first -of -its -kind screening tools for explosive and energetic compounds directly in the
settings where they are needed with high efficiency , reduced cost , and simplicity with ease
of use . Unlike current explosives detectors , this system is based on calorimetric
techniques that are inherently capable of providing direct measurements of energy release
potential and therefore do not depend on prior knowledge of familiar compounds .
The microfabricated calorimetry instrument consists of (i ) a thermal control
module incorporating arrays of microfabricated heaters and temperature sensors , as well
as any necessary electronic interconnections , and (ii ) a sample encapsulation module
incorporating etched enclosures designed to accommodate either solid or liquid samples . Initial work has led to successful fabrication of a chip capable of sampling nano -sized
solid or liquid compounds . Control algorithms incorporating the DSC principle have also
been written using LabVIEW . Device performance of the original and redesigned chips
were tested by studying the thermal transitions associated with the boiling points of
acetone and pentane . With the redesigned chip , the heat loss issue was reduced : the
measured input heat was reduced from 32 times of the required energy to 5 times of the
required energy . Future work will focus on modifying the chip design and control
algorithm to improve accuracy and sensitivity , developing a trace analysis software to link
it to a database of explosive information , and adapting different fabrication procedures for
high temperature operation and large scale production . |