A theoretical investigation of gas conduction effects on multilayer insulation performance

The thermal performance of multilayer insulation hlankets depends on three (interacting) modes of energy transfer: radiation between the radiation shields, gas conduction in the residual interstitial gas and solid conduction via the contacting interfaces. The contribution of the gas conduction depends on the interstitial gas and its pressure,...

Transport of heat and mass in a two-phase mixture: From a continuous to a discontinuous description

We present a theory that describes the transport properties of the interfacial region with respect to heat and mass transfer. Postulating the local Gibbs relation for a continuous description inside the interfacial region, we derive the description of the Gibbs surface in terms of excess densities and fluxes along the surface. We introduce...

Thermal-Diffusivity-Based Frequency References in Standard CMOS

In recent years, a lot of research has been devoted to the realization of accurate integrated frequency references. A thermal-diffusivity-based (TD) frequency reference provides an alternative method of on-chip frequency generation in standard CMOS technology. A frequency-locked loop locks the output frequency of an oscillator to the accurate...

A Low-Power CMOS Wind Sensor with Corner Heaters

Integrated Temperature Sensors based on Heat Diffusion

This thesis describes the theory, design and implementation of a new class of integrated temperature sensors, based on heat diffusion. In such sensors, temperature is sensed by measuring the time it takes for heat to diffuse through silicon. An on-chip thermal delay can be determined by geometry and the thermal diffusivity of silicon, and since...

A Highly-Scalable Thermal-Diffusivity-Based Temperature Sensor

A highly digital temperature sensor, based on the thermal diffusivity of silicon, for thermal management applications has been reported. Recently, Thermal-Diffusivity based temperature sensors have undergone a radical change from an analog-based readout architecture to a more digital VCO-based one. However the more digital approach led to...

Compact Thermal-Diffusivity-Based Temperature Sensors in 40-nm CMOS for SoC Thermal Monitoring

An array of temperature sensors based on the thermal diffusivity (TD) of bulk silicon has been realized in a standard 40-nm CMOS process. In each TD sensor, a highly digital voltage-controlled oscillator-based Σ Δ ADC digitizes the temperature-dependent phase shift of an electrothermal filter (ETF). A phase calibration scheme is used to...

Compact Thermal Diffusivity Sensors for On-Chip Thermal Management

Today’s systems-on-chip (SOCs) and microprocessors are complex systems that require multiple temperature sensors to monitor temperature variations in multiple spots on a single silicon die. For such thermal management applications, specialized compact and fast temperature sensors are required. This is necessary because executing an intensive...

Thermodynamic properties of the actinide oxides solid solutions: A calorimetric study

The work presented in this thesis provides new data on the behaviour of the binary mixed actinide oxides of the following systems: (Th,Pu)O2, (U,Pu)O2, (Th,U)O2, (U,Am)O2. The results were obtained by performing measurements in a large temperature interval, for some compounds the thermodynamic properties were studied in the range from about 2 to...

A Self-Calibrated Hybrid Thermal-Diffusivity/Resistor-Based Temperature Sensor

This article describes a hybrid temperature sensor in which an accurate, but energy-inefficient, thermal diffusivity (TD) sensor is used to calibrate an inaccurate, but efficient, resistor-based sensor. The latter is based on silicided polysilicon resistors embedded in a Wien-bridge (WB) filter, while the former is based on an electrothermal...

New measurement methods and physico-chemical properties of the MSFR salt

The Molten Salt Reactor (MSR) is one of the six types of Generation IV nuclear energy systems with the main goals of sustainability, safety, reliability, economic competitiveness and proliferation resistance. This technology has spawn interest worldwide. Numerous universities, institutes and companies are carrying out research projects related...

Multiplexed thermal-diffusivity-based temperature sensors

Due to the precise lithography and highly pure silicon used in IC technology, thermal-diffusivity (TD) temperature sensors can achieve high accuracy without the need for trimming. TD sensors employ electrothermal filters (ETFs) to measure the thermal diffusivity of silicon, i.e. the rate at which heat diffuses through silicon, which is a well...

Will SiOx-pinholes for SiOx/poly-Si passivating contact enhance the passivation quality?

Passivating contacts based on poly-Si have enabled record-high c-Si solar cell efficiencies due to their excellent surface passivation quality and carrier selectivity. The eventual existence of pinholes within the ultra-thin SiOx layer is one of the key factors for carrier collection, beside the tunneling mechanism. However, pinholes are usually...

Thermal conductivity of binary ceramic composites made of insulating and conducting materials comprising full composition range – Applied to yttria partially stabilized zirconia and molybdenum disilicide

The thermal diffusivity and conductivity of dense and porous binary composites having an insulating and conducting phase were studied across its entire composition range. Experimental evaluation has been performed with MoSi₂ particles embedded into yttria partially stabilized zirconia (YPSZ) as prepared by spark plasma sintering ...