12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Thermophones by Quantum Mechanics Thomas Prevenslik QED Radiations Discovery Bay, Hong Kong 1

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Introduction Over a century ago, Stokes communicated to the Royal Society in 1880 the finding by Preece that electrical wires produced sound. In 1914, Rayleigh reported de Lange’s thermophone invention to the Royal Society 2

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Theory First presented by Arnold & Crandall in Classical heat transfer was used to determine the temperatures that cause the film vibrations that produce sound from air pressure changes 3

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Modified Theory In 2008, Xiao et al. showed sound was produced in thin films of CNTs. But the data could not be fit to the Arnold & Crandall theory. Modification allowed additional heat loss Q o to the air. 4

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Problems with Theory Ultrasonic vibration of the film to produce pressure changes was not found. Film temperature responds fast to cause pressure changes of colliding air molecules? 5 * “Thermally induced ultrasonic emission from porous silicon,” Letters to Nature, Vol. 400, 26 August Shimoda et al. * previously questioned whether the film can even respond at ultrasonic frequencies. “One might think the ultrasound generation by heat exchange is not possible, as the thermal conduction is too slow. But we report here … an efficient ultrasound emitter”

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Hypothesis Thermophones by QM produce sound without vibration by emitting EM radiation that is absorbed in the air surroundings QM = Quantum Mechanics EM = Electromagnetic 6

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Heat Capacity – Classical v. QM 7 Nanoscale kT eV Classical QM

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Conservation of EM Energy Recall from QM, QED photons of wavelength are created by supplying EM energy to a box having sides separated by / 2. For thin film, = 2 d n r Conservation proceeds by creating QED photons inside the nanostructure - by frequency up - conversion of absorbed EM energy to the fundamental resonance of the nanostructure. QED = Quantum ElectroDynamics 8

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas QED Induced Heat Transfer 9 Non Thermal Emission E = Photon Planck Energy dN/dt = Photon Rate  T = 0

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Classical heat transfer can not explain the reduced conductivity found in thin film experiments. Explanations based on revisions to Fourier theory by phonons as quanta in the BTE are difficult to understand and usually concluded by hand-waving 10 * See T. Prevenslik, “Heat Transfer in Thin Films,” Third Int. Conf. on Quantum, Nano and Micro Technologies, ICQNM 2009, February 1-6, Cancun, 2009: and proceedings of MNHMT09 Micro/Nanoscale Heat and Mass Transfer International Conference, December 18-21, 2009, Shanghai. Thermophones as Thin Films*

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Thin Film – Reduced Conductivity 11 QED Heat Transfer Q Cond = Q Joule - Q QED ~ 0 K eff  T = (Q Joule - Q QED ) (d f + d S ) / A  T small, K eff ~ Bulk Q QED Q Cond TT Current Approach Q Cond = Q Joule K eff  T = Q cond (d f + d S )/A  T large, K eff small Q Joule Effective Conductivity K eff = [K f / d f + K S / d S ] / (d f + d S ) Film Substrate dfdf dSdS KfKf KSKS

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Thin Film - QED Estimate 12

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Thermophones by QM 13

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Thermophone – QM Response 14

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Thermophone - Conclusions Thermophones produce sound by the absorption of QED emission in the surrounding air. Prompt QED emission allows sound at ultrasonic frequencies to be produced without temperature changes or vibrations. 15

12 th Intersociety Conf. Thermal Phenomenon in Electronic Systems ; June 2-5, 2010, Las Vegas Questions & Papers