Microwave dielectric heating of drops in microfluidic devices.

نویسندگان

  • David Issadore
  • Katherine J Humphry
  • Keith A Brown
  • Lori Sandberg
  • David A Weitz
  • Robert M Westervelt
چکیده

We present a technique to locally and rapidly heat water drops in microfluidic devices with microwave dielectric heating. Water absorbs microwave power more efficiently than polymers, glass, and oils due to its permanent molecular dipole moment that has large dielectric loss at GHz frequencies. The relevant heat capacity of the system is a single thermally isolated picolitre-scale drop of water, enabling very fast thermal cycling. We demonstrate microwave dielectric heating in a microfluidic device that integrates a flow-focusing drop maker, drop splitters, and metal electrodes to locally deliver microwave power from an inexpensive, commercially available 3.0 GHz source and amplifier. The temperature change of the drops is measured by observing the temperature dependent fluorescence intensity of cadmium selenide nanocrystals suspended in the water drops. We demonstrate characteristic heating times as short as 15 ms to steady-state temperature changes as large as 30 degrees C above the base temperature of the microfluidic device. Many common biological and chemical applications require rapid and local control of temperature and can benefit from this new technique.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Efficient Microwave Heating and Dielectric Characterization of Microfluidic Systems

ABSTRACT This paper presents a 2.45 GHz microwave cavity resonator with the novel dual function of both sensitive dielectric characterisation and directed, volumetric heating of fluids in a microfluidic chip. This method is shown to have a higher efficiency (>90 % for methanol), higher rate of heating and more accurate control than previous microfluidic microwave heating methods [1], [2]. The s...

متن کامل

Microwave dielectric heating of non-aqueous droplets in a microfluidic device for nanoparticle synthesis.

We describe a microfluidic device with an integrated microwave heater specifically designed to dielectrically heat non-aqueous droplets using time-varying electrical fields with the frequency range between 700 and 900 MHz. The precise control of frequency, power, temperature and duration of the applied field opens up new vistas for experiments not attainable by conventional microwave heating. W...

متن کامل

High electric field effects on gigahertz dielectric properties of water measured with microwave microfluidic devices.

Silicon microstrip line devices with 260 nm planar microfluidic channels are fabricated and used to investigate water dielectric saturation effects. Microwave scattering parameter measurements are conducted from 1 to 16 GHz under different uniform dc electric fields. When the applied dc field is increased to approximately 1 MV/cm, the measured transmission coefficient S(21) is increased up to 1...

متن کامل

Infrared Thermopile Temperature Measurement Technique in Microwave Heating Systems

Temperature measurement in microwave systems is essential for thermally driven processes, namely, catalytic reactions and ceramic sintering. Although, the application of direct thermometry methods, namely, thermocouples, have been commonly articulated in the available literature, however, contacted temperature measurement mechanisms have aroused concerns associated with the disruption of the el...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Lab on a chip

دوره 9 12  شماره 

صفحات  -

تاریخ انتشار 2009