Smaller Heat Sink Research Articles

Toward tiny high-power-density thermoelectric harvesters

Thermoelectric (TE) generators (TEGs) have recently attracted significant attention for harvesting ubiquitous heat energy to power industrial sensor nodes or wearable and implantable electronics. Such applications require that a small, fitted heat sink be incorporated into a tiny harvester to ensure conformal deployment and ease of use. Since the small heat sink will exhibit very poor heat rejection performance, the optimal structural design of the TEG device and the proper selection of its constituent TE materials are extremely important to ensure that sufficient electric power is provided to the connected post-stage circuits. Regrettably, the traditional forward design strategies, i.e., material-to-device and device-to-harvester, are often disconnected from one another and fail to form a complete chain, thereby presenting a fundamental challenge in achieving ultrahigh-power-density harvesters. Here we present a zero-dimensional model for a tiny harvester to establish a set of new metrics (not limited to the figure of merit zT) that can be used to determine the optimal TE material and to directly deduce the optimal configuration of the TEG for guaranteeing the maximum output power at various load conditions, making backward design strategy possible. Two tiny harvesters are accordingly fabricated and exhibit areal power densities 52 and 94 times that of a harvester incorporating a commercial TEG, with identical amounts of TE material used for each.

Experimental Evaluation of Nanofluid for Improved Cooling Efficiency in an AL Mini Channel Heat Sink

Abstract: Efficient heat transfer has become major need these days. In this thesis, both experimental and CFD investigations have to be carried out to evaluate the cooling performance of a mini-channel consisting of fins on upper surface of flat plate. Nano fluids contain a small fraction of solid nano particles in base fluids flowing through groves in bottom plate attached with heater at base. Nano fluids cools small channel heat sinks, have been anticipated to be an excellent heat dissipation method for the next generation electronic devices. Computational Fluid Dynamics (CFD) simulations is to be carried out to study the heat sinks heat transfer mechanism. The sectional geometry of channels affects the flow and heat transfer characteristics of mini channel heat sinks. The heat transfer principle states that maximum heat transfer is achieved in mini channels with minimum pressure drop across it. In this research work the experimental and numerical investigation for the improved heat transfer characteristics of mini channel heat sink using Al2O3/water nano with (1 and 2 % volume fraction) fluid is to be done. The fluid flow characteristics are also analysed for the serpentine shaped mini channel. Heating element of 130 W capacities is to be used to heat up the heating element of base plate. Keywords: Heat, Fluids, Heating, Nano, Fraction, Flow, Sink, Channel, Plate, Aluminum.

Five‐Year Analysis of Evaposublimation Characteristics and Its Role on Surface Energy Balance SEB on a Midlatitude Continental Glacier

AbstractAs a principal pathway of moisture loss of cryosphere, the sublimation of snow or ice needs to absorb a high amount of energy to complete the phase transition, while related researches on how sublimation affects surface energy balance (SEB) are still insufficient, causing unclear conclusions. To characterize the seasonal variation of a mountain glacier's sublimation or evaporation and analysis its role on SEB, the meteorological and glaciological data over five‐year measurement period (2016–2020) were obtained on the top of August‐one glacier. In the non‐melt period of a year (January–May and October–December), sensible heat flux H was the dominant energy contributor to glacier surface (76%), followed by net radiation Rnet (22%). Sublimation removed average 85 mm (0.4 mm/day) of water vapor from surface for the dry and windy weather, and the latent heat flux of sublimation LEE accounted for 33% of energy sinks (67% of energy was stored in the glacier Qs). In the melt period (June–September), evaposublimation (mainly composed of evaporation) reached to 36 mm (0.3 mm/day), but LEE only played a small heat sink (14%) and the Qm (the energy for melting) had the largest proportion (70%). Rnet and H contributed 81% and 15% of surface energy, respectively. Obviously, under the global climate warming, the sublimation of non‐melt period seems to be effective in decrease the heating rate of glacier surface.

Оцінка зносу стрілчастих лап культиватора і технологія їх зміцнення

In recent years, research and developments related to the creation of new areas using nanotechnology take a special place in scientific achievements. They are developed and widely used in Physics, Chemistry, Biology, Electronics, Medicine, Food Production and to a much lesser extent in Engineering. This is due to the fact that there are different requirements to parts and products used in mechanical engineering, they have a complex shape, are made of different materials, production methods, heat treatment. While operating, their working layer undergoes degradation with a significant change in structure and their hardening using nanocoatings may turn out to be ineffective in both technical and economic aspects. In this case, only a specific approach, which is determined by comprehensive research with identification of the main factors of parts damageability in specific production and operation conditions, can be expedient. In addition, in some cases for hardening, repair and restoration of parts it is expedient to use surfacing methods with the introduction of modifying agents in a liquid bath during crystallization. These modifying agents are nano-and dispersed diamonds, which make it possible to adjust temperature parameters of crystallization, grain size, and stress level. This approach allows using high-alloyed, high-carbon electrodes even for thin-walled steel and cast iron products. In this case, the diamond inclusions additive plays the role of micro-refrigerators, which significantly change the crystallization temperature range. It is important to determine the optimal dose of the introduction of such a modifier and ensure uniform distribution the components in the coating. The presented work is devoted to the new technology development of hardening of cultivator blades metal with nano-and dispersed diamond additives, which are the part of the detonation charge from the disposal of ammunition. Nowadays, in agriculture, a large number of tillage implements are used for tillage, the working bodies of which are sweep blades. They are operated under conditions of abrasive particles impact, and this is accompanied by their intense wear with a corresponding change in the geometric dimensions of the main working surfaces. The worn sweep blades significantly reduce efficiency and quality of the carried-out work. The analysis of the effective choice of surfacing materials for hardening and improving their performance has been carried out and the nature of wear has been evaluated in order to identify areas of maximum damage and to determine the optimal method. It is known that T-590 and T-620 electrodes are used for the restoration surfacing of tillage implements. It was found the hardfacing of thin-walled parts is accompanied by a smaller heat sink and, in some cases, they are flooded with defect formation. To reduce it, a non-magnetic fraction of detonation charge from ammunition disposalin the form of an electrode modification was introduced, which ensured the uniform distribution the components in the coating. The method of the X-ray electron-probe analysis has been used to evaluate features of structure formation and component distribution along the perimeter of the coating. It was found out that this method of hardening reduces heat input and increases the microhardness and wear resistance of the surfaced coating, reduces the transition zone and thermal impact. The recommended method of metal hardening of new cultivator blades is to apply stripes on the point tip and wings of blades. On the basis of the nature of wear, the expediency of applying stripes on the point tip of the cultivator blade from the front side, and on wings from the rear side, is justified. The optimal geometrical dimensions of hardening stripes and their location on the blade are presented, which allows minimizing the local stresses and increasing wear resistance.

Experiment and simulation analysis of oriented cut copper fiber heat sink for LED water cooling

In order to address the heat dissipation issue of LED light sources, an oriented cut copper fiber heat sink (Oriented-CCFHS) for LED water cooling was designed and prepared in this paper. The heat transfer performance and flow characteristics of Oriented-CCFHS, cavity heat sink, small channel heat sink, and random cut copper fiber heat sink (Random-CCFHS) were compared by experiments. Flow and heat transfer performance are obtained through Fluent simulation. Both experiment and simulation results show that the heat transfer performance of Random-CCFHS and Oriented-CCFHS were better than that of cavity heat sink and small channel heat sink. Compared with Random-CCFHS, the heat transfer performance of the Oriented-CCFHS is slightly worse, but the pressure drop is significantly smaller. The comprehensive heat transfer performance of Oriented-CCFHS is superior to that of Random-CCFHS with the same porosity. The performance of the oriented sintered heat sink under different structural parameters is predicted by numerical model. The heat transfer performance of the sintered core is optimal when the thickness of the sintered core is 2 mm. The longer sintered core with oriented copper fiber, the greater the pressure drop of heat sink and the stronger the heat transfer performance, however, the enhancement trend gradually slows down.

Diamond semiconductor performances in power electronics applications

This paper proposes a system-level comparison between diamond and silicon carbide (SiC) power devices. It highlights the benefits of diamond semiconductors for power electronics applications. Actual diamond power devices were fabricated and characterised (DC, AC small-signal, large-signal power switching in a buck converter). Models of the diamond devices are discussed based on the experimental data, and the expected performances of the future diamond semiconductors in power converters are presented. These performances are compared to the commercialised SiC Schottky diodes for a given application. Our analysis shows that diamond devices can be used to increase the performance of power converters, especially at high temperatures. We demonstrate that for a junction temperature of 450 K, diamond semiconductors can divide the semiconductor losses and heatsink volume by three, in comparison with SiC devices. We also demonstrate that the switching frequency with diamond devices can be five times higher than with SiC devices, with lower total semiconductor losses and smaller heatsink in diamond-based power converters. This system-level analysis clearly shows the future improvements in the efficiency and power densities of power converters thanks to diamond power devices. The need for management of the specific junction temperature, which is required in order to exploit all of the properties of diamonds, is demonstrated and discussed.

Experimental study of the performance of cutting copper fiber oriented sintered heat sinks for the water cooling of LEDs

LED light sources have been gradually applied in plant factories, but the heat dissipation of LED leads to high energy consumption. Considering the water irrigation systems of plant factories, a cutting copper fiber oriented sintered heat sink (CCFOSHS) is proposed for water cooling of LEDs. The heat transfer and flow performances of CCFOSHS were investigated by experiments, and compared with cutting copper fiber random sintered heat sink (CCFRSHS) and traditional small channel heat sink. Influences of porosity and equivalent diameter of fibers on heat transfer and flow performances of CCFOSHS are analyzed. Results demonstrate that compared to CCFRSHS, heat transfer performances of CCFOSHS are slightly worse, but the direction of fiber causes a lower pressure drop and CCFOSHS has better comprehensive heat transfer performance. With the decrease of porosity, heat transfer performances of CCFOSHS are enhanced slightly, but pressure drops increase distinctly. Heat transfer performances of CCFOSHS are not sensitive to the equivalent diameter of fibers. The smaller equivalent diameter of the fibers leads to a higher pressure drop. Especially when the equivalent diameter of fibers is 195.12 μm, CCFOSHS with 80% porosity, has better temperature uniformity.

Design of Class D Audio Power Amplifier Suitable to Hearing Aid Devices

An amplifier is an electronic circuit that improves the strength of the signal. Using an amplifier in an audio system is essential to improve the strength of the signal. Based on different applications and specifications different types of amplifiers are used. Generally in an audio system, the input signal is amplified to a minimum required power level and then the speaker is driven by it. Conventionally, the output stage of an audio amplifier uses Class-A or Class-AB operating in a linear transfer region. The power efficiency of the Class-D amplifier has a better output efficiency compared to Class-A and Class-AB amplifiers, and its distortion is lower than that of the Class-C amplifier. This is based on a known fact that the Class D amplifier has a switching action in which the transistors are either completely on or off. As a result, the amplification is achieved with no power dissipation. Hence, the size of the amplifier can be highly reduced and a smaller heat sink is required. This paper focuses on designing a Class-D power amplifier which is suitable for hearing aid devices to deliver 500mW output power and for the THD to be less than 3%. The circuit implementation is done using UMC high voltage 0.18μm technology. This amplifier consists of three stages such as the modulation stage, the driver stage, the bridge stage, and the demodulation stage. Unfortunately, the Class-D power amplifier has inherent non-linear distortion problems, which is more significant than conventional audio power amplifiers. In this thesis, negative feedback is employed to reduce THD. Without feedback, the THD is obtained as above 3%. By employing feedback, the THD was reduced by 1.96dB. This design result is discussed and through to realization; whereupon the effectiveness of each of the implementation is evaluated.

Experimental investigation into the thermal augmentation of pigmented asphalt

Asphalt binder is a temperature dependent material and is more susceptible to damage at higher temperatures. During summers, low thermal conduction and high specific heat of conventional asphalt results in extreme pavement surface temperatures and increased vulnerability. The situation demands for use of additives/modifiers that could help reduce pavement surface temperature. Thermal conduction of pigment modified/non-black asphalt mixtures is investigated in this research. Study focuses both on heating and cooling phase w.r.t time. Asphalt mixtures were evaluated for thermal conduction using larger heat sink with internal dimensions of 100×100×50 mm3. However, bituminous mixtures were examined in smaller heat sink with internal dimensions of 60×60×25 mm3. Both heat sinks were subjected to 800, 1000, and 1200 W/m2 heat flux and measurements were recorded accordingly. DC power supply was used as a heating source and silicon heater as a heating surface. Sinks were connected with data logger via calibrated K-type thermocouples. Iron oxide red and Titanium dioxide white pigments are used to decolour the black mixes. 4% by weight of total mix of each pigment is used to colour the black binder. Results have shown that at the end of 3 h of heating phase, pigment modified samples remain 8–10 °C cooler in case of bitumen binder and 4–5 °C cooler in case of asphalt mixtures. At the end of 2 h of cooling phase, a difference of 3–4 °C was noted between pigmented and conventional asphalt. Results also show that pigmented mixtures not only conduct more heat but also cool faster. Quantitatively, pigmented mixtures conduct 10%–15% more heat in comparison to the unmodified/black asphalt mixtures. The reduction in temperature susceptibility of pigmented mixtures may also help improve their high temperature performance.

PENGUAT KELAS D DENGAN METODE SUMMING INTEGRATOR

A class D amplifier is one in which the output transistors are operated as switches. When a transistor is off, the current through it is zero and when it is on, the voltage across it is small, ideally zero. Thus the power dissipation is very low, so it requires a smaller heat sink for the amplifier. Class D amplifier operation is based on analog principles and there is no digital encoding of the signal. Before the emergence of class D amplifiers, the standard classes were class A, class AB, class B, and class C. The classic method for generating signals driving a transistor MOSFET is to use a comparator. One input is driven by an incoming audio signal, and the other by a triangle wave or a sawtooth wave at the required switching frequency. The frequency of a triangular or sawtooth wave must be higher than the audio input. MOSFET transistors work in a complementary manner that operates as a switch. Triangle waves are usually generated by square waves fed to the integrator circuit. So the main part of processing audio signals into PWM (Pulse Width Modulation) is the integrator and comparator. In this paper, we will discuss the work of a class D amplifier system using the summing integrator method as its main part.

A multichannel microcalorimetric system

A new generation isothermal multichannel microcalorimetry system based on an earlier reported system which has been commercialised under the name “Thermal Activity Monitor” (TAM) is described and evaluated. The system has a modular design constituting a thermostat that accommodates up to four calorimetric units. The temperature stability of the thermostat has been improved 100-fold compared to the original TAM mainly due to novel technology for absolute temperature measurements consisting of a platinum resistance sensor combined with a high-resolution thermoelectric (TE) module housed in an aluminium body for temperature fluctuation measurements. In combination with the continuous liquid overflow design similar to that of the original TAM with an inbuilt Peltier cooling/heating system forming part of a single feedback regulation system, temperature drifts/fluctuations over 24 h better than ±10 µK have been achieved. Besides the isothermal mode, the thermostat can be controlled to perform temperature ramps with rates from close to 0 up to 2 K h−1. Two basic designs of twin heat flow calorimeters are described. One is similar to those originally reported having the sample and reference sides mirrored horizontally, and with a solid heat sink time constant of 6000 s. The other has the sample and reference mirrored on the vertical axis with a solid heat sink time constant of 500 s making it considerably smaller. Both calorimeters are equipped with insertion ampoule holders that can hold 4 mL reaction volume. The lowest observed long-term signal stability among a population of data from the two calorimeters was ±17 nW/24 h for the calorimeter with the larger heat sink and ±50 nW/24 h for the calorimeter with the smaller heat sink. Test experiments indicated the absence of significant systematic errors for the former calorimeter type while a maximum of 2–3% error was observed for the latter type. This difference between the two calorimeter types was attributed to different positioning of the TE sensors relative to the calibration heater.

Advanced Natural Convection Cooling Designs for Light-Emitting Diode Bulb Systems

The movement to light-emitting diode (LED) lighting systems worldwide is accelerating quickly as energy savings and reduction in hazardous materials increase in importance. Government regulations and rapidly lowering prices help to further this trend. Today's strong drive is to replace light bulbs of common outputs (60 W, 75 W, and 100 W) without resorting to compact fluorescent (CFL) bulbs containing mercury while maintaining the standard industry bulb size and shape referred to as A19. For many bulb designs, this A19 size and shape restriction forces a small heat sink which is barely capable of dissipating heat for 60 W equivalent LED bulbs with natural convection for today's LED efficacies. 75 W and 100 W equivalent bulbs require larger sizes, some method of forced cooling, or some unusual liquid cooling system; generally none of these approaches are desirable for light bulbs from a consumer point of view. Thus, there is interest in developing natural convection cooled A19 light bulb designs for LEDs that cool far more effectively than today's current designs. Current A19 size heat sink designs typically have thermal resistances of 5–7 °C/W. This paper presents designs utilizing the effects of chimney cooling, well developed for other fields that reduce heat sink resistances by significant amounts while meeting all other requirements for bulb system design. Numerical studies and test data show performance of 3–4 °C/W for various orientations including methods for keeping the chimney partially active in horizontal orientations. Significant parameters are also studied with effects upon performance. The simulations are in good agreement with the experimental data. Such chimney-based designs are shown to enable 75 W and 100 W equivalent LED light bulb designs critical for faster penetration of LED systems into general lighting applications.

Modelling of superheated steam drying for combined heat and power at a corn ethanol plant using Aspen Plus software

A superheated steam drying (SSD) model was developed in Aspen Plus software to determine energy and water recovery for drying the co-products in a corn ethanol plant. The SSD was integrated into a biomass integrated gasification combined cycle (BIGCC) heat and power production model developed for a 190 million litre per year corn ethanol plant. The BIGCC system was fuelled with either corn stover or a mixture of syrup and corn stover at a rate of 110 MW. Results were compared to estimates for steam tube drying (STD). Energy consumed for the SSD was 759–804 kJ kg−1 of water removed compared to 2660–2690 kJ kg−1 for the STD. Approximately 1.3 l of water were recovered per litre of ethanol produced with the SSD, with none for the STD. Less power was generated in the BIGCC system with SSD due to its smaller heat sink than for the BIGCC system with STD.

Thermal management of a multiple mini-channel heat sink by the integration of a thermal responsive shape memory material

In this paper, a novel application of a thermo-responsive shape memory polymer (SMP) is proposed to smart-control the forced flow of water in a multi mini-channel heat sink. In particular, it is reported that millimeter-sized cylinders made of SMP could be used to smartly obstruct the fluid flow by adapting the flow cross section to the heat load to be removed. By integrating the sensing, the control and the actuation functions within a unique, millimeter-sized device, these micro-valves, unlike the traditional actuators normally used for flow control, could be easily embedded into small heat sinks, with significant space and energy saving, useful, in particular, in systems where several miniaturized components have to be cooled concurrently, such as the modern mainframes or the concentrated photovoltaic solar cells.Two possible configurations for the SMP were considered in this study: an “open” configuration, without any obstruction of the water flow free and an “obstructed” configuration, with the millimeter-sized cylinder partially occupying the mini-channel. A numerical, steady state analysis was carried out with water in single-phase forced convection, to determine the effect of these two states on the internal fluid flow characteristics under different conditions of heat flux and pressure drop and to evaluate the overall thermal behavior of the smart-controlled multiple mini-channel heat sink in terms of ability to control the temperature of the system and to reduce the energy consumption.

HEAT TRANSFER ENHANCEMENT OF SMALL SCALE HEAT SINKS USING VIBRATING PIN FIN

Heat sinks are widely adopted in electronics coolin g together with different technologies to enhance t he cooling process. For the small electronics applicat ion, the small scale pin fins heat sinks are extens ively used to dissipate heat in electronics devices. Due to the limit of space in the small devices, it is i mpossible to increase heat transfer area. In order to improve the heat transfer performance, the applying the fo rced vibration is one of challenging method. This study applies the vibration frequency between 50 to 1,000 Hz to pin fins heat sinks. The results of numerical si mulation clearly show satisfied heat transfer augme ntation. However, the Pressure drop significantly increases with frequency. This phenomenon affects the heat tr ansfer enhancement performance that it increases with freq uency until certain value then it drops rapidly. Th e results of this study can help designing heat sinks for ele ctronics cooling by employing the concept of vibrat ion.

Advanced Passive Thermal Management for LED Bulb Systems

The movement to LED lighting systems worldwide is accelerating quickly as energy savings and reduction of hazardous substances (RoHS) increase in importance. Furthering this trend are government regulations, rebate programs and declining prices. The market drive today is to replace light bulbs of common outputs (60W, 75W and 100W) without resorting to Compact Fluorescent (CFL) bulbs containing mercury while maintaining the standard industry bulb size and shape referred to as A19 for fixture retrofitting. This A19 size and shape restriction causes a small heat sink which is only capable of dissipating heat for 60W equivalent LED bulbs with natural convection. 75W and 100W equivalent bulbs require larger sizes, some method of forced cooling, or some unusual liquid cooling system; generally none of these approaches are desirable for light bulbs from a consumer point of view. Thus, there is interest in developing natural convection cooled A19 light bulb designs for LEDs that cool far more effectively than today's current designs. Current A19 size heat sink designs typically have thermal resistances of 5–7 °C/W. A more efficient method of cooling can be created using a chimney-based design to lower system thermal resistances below 4 °C/W while meeting all other requirements for bulb system design. Numerical studies and test data are in good agreement for various orientations including methods for keeping the chimney partially active in horizontal orientations. Such chimney-based designs are capable of cooling 75W and 100W equivalent LED light bulbs in the limited volume constraints of A19-size devices.

Effect of Flow Pulsation on the Heat Transfer Performance of a Minichannel Heat Sink

Heat sinks with liquid forced convection in microchannels are targeted for cooling electronic devices with a high dissipated power density. Given the inherent stability problems associated with two-phase microchannel heat transfer, this paper investigates experimentally the potential for enhancing single-phase convection cooling rates by applying pulsating flow. To this end, a pulsator device is developed which allows independent continuous control of pulsation amplitude and frequency. For a single minichannel geometry (1.9 mm hydraulic diameter) and a wide range of parameters (steady and pulsating Reynolds number, Womersley number), experimental results are presented for the overall heat transfer enhancement compared to the steady flow case. Enhancement factors up to 40% are observed for the investigated parameter range (Reynolds number between 100 and 650, ratio of pulsating to steady Reynolds number between 0.002 and 3, Womersley number between 6 and 17). Two regimes can be discerned: for low pulsation amplitude (corresponding to a ratio of pulsating to steady Reynolds number below 0.2), a small heat transfer reduction is observed similar to earlier analytical and numerical predictions. For higher amplitudes, a significant heat transfer enhancement is observed with a good correspondence to a power law correlation. This work establishes a reference case for future studies of the effect of flow unsteadiness in small scale heat sinks.

Cooling of minichannel heat sink using nanofluids

Nanofluids contain a small fraction of solid nanoparticles in base fluids. Nanofluids cooled small channel heat sinks, have been anticipated to be an excellent heat dissipation method for the next generation electronic devices. In this study, nanofluids are used with different volume fractions of nanoparticles as a coolant for the minichannel. Al2O3–water nanofluid and TiO2–water nanofluid were tested for the copper minichannel heat sink, with the bottom of 20×20mm laminar flow as a coolant, through hydraulic diameters. The result showed that adding Al2O3 nanoparticles to water at 4% of volume fractions, enhanced the thermal conductivity by 11.98% and by dispersing TiO2 to the base fluid, was 9.97%. It was found that using nanofluid such as Al2O3–water instead of water, improved the cooling by 2.95% to 17.32% and by using TiO2–water, 1.88% to 16.53% was achieved. The highest pumping power by using Al2O3–water and TiO2–water at 4vol.% and 0.1m/s was 0.000552W and at 4vol.% and 1.5m/s was 0.12437W.

Topology Optimization Using the SIMP Method for Multiobjective Conductive Problems

The efficient cooling of a finite-size volume generating heat, including adiabatic boundary conditions with the exception of a small heat sink, poses the problem of optimal allocation of high-conductivity material. Among the structural optimization methods, this article couples solid isotropic material with penalization parametrization (SIMP) with an aggregated objective function approach (AOF) to tackle this topology optimization problem through a multiobjective strategy. Both average and variance temperature-reduction problems is solved by the identification of Pareto fronts, which are highly dependent on the quantity of the high-conductivity material. This study also underlines the link between the sensitivity analysis of both objective functions, which is required by the method of moving asymptotes (MMA). Furthermore, additional calculations have been done to include variations in heat-generation rate between two conductive materials by means of an additional penalization strategy. The main conclusion deals with the possibility of finding an acceptable trade-off between average and variance objective functions thanks to the convex shape of Pareto frontiers.

Metal-filled carbon nanotube based optical nanoantennas: bubbling, reshaping, and in situ characterization

Controlled fabrication of metal nanospheres on nanotube tips for optical antennas is investigated experimentally. Resembling soap bubble blowing using a straw, the fabrication process is based on nanofluidic mass delivery at the attogram scale using metal-filled carbon nanotubes (m@CNTs). Two methods have been investigated including electron-beam-induced bubbling (EBIB) and electromigration-based bubbling (EMBB). EBIB involves the bombardment of an m@CNT with a high energy electron beam of a transmission electron microscope (TEM), with which the encapsulated metal is melted and flowed out from the nanotube, generating a metallic particle on a nanotube tip. In the case where the encapsulated materials inside the CNT have a higher melting point than what the beam energy can reach, EMBB is an optional process to apply. Experiments show that, under a low bias (2.0-2.5 V), nanoparticles can be formed on the nanotube tips. The final shape and crystallinity of the nanoparticles are determined by the cooling rate. Instant cooling occurs with a relatively large heat sink and causes the instant shaping of the solid deposit, which is typically similar to the shape of the molten state. With a smaller heat sink as a probe, it is possible to keep the deposit in a molten state. Instant cooling by separating the deposit from the probe can result in a perfect sphere. Surface and volume plasmons characterized with electron energy loss spectroscopy (EELS) prove that resonance occurs between a pair of as-fabricated spheres on the tip structures. Such spheres on pillars can serve as nano-optical antennas and will enable devices such as scanning near-field optical microscope (SNOM) probes, scanning anodes for field emitters, and single molecule detectors, which can find applications in bio-sensing, molecular detection, and high-resolution optical microscopy.