Additive manufacturing (AM) is currently on the verge of redefining the way we produce and manufacture things. AM encompasses many technologies and subsets, which are all joint by a common denominator; they build three dimensional (3D) objects by adding materials layer-upon-layer. This family of methods can do so, whether the material is plastic, concrete, metallic or living cells which can function as organs. AM manufacturing at the micro scale introduces new capabilities for the AM family that has been proven difficult to achieve with established AM methods at the macro scale. Electrohydrodynamic jet (E-jet or EHD jet) printing is a micro AM technique which has the ability to print at high resolution and speed by exploiting physical phenomena to generate droplets using the means of an electric field. However, when printing metallic materials, this method requires nanoparticles for deposition. To obtain a stable structure the material needs to be sintered, after which the deposited material is left with a porous structure. In contrary, electrochemical methods using the well-known deposition mechanism of electroplating, can deposit dense and pure structures with the downside of slow deposition. In this thesis, a new method is proposed to micro additive manufacturing by merging an already existing technology EHD with simple electrochemistry. By doing so, we demonstrate that it is possible to print metallic structures at the micro- and nanoscale with high speeds, without the need for presynthesized nanoparticles. To achieve this, a printing setup was designed and built. Using a sacrificial wire and the solvent acetonitrile, metallic building blocks such as lines, pillars and other geometric features could be printed in copper, silver, and gold with a minimum feature size of 200 nm. A voltage dependence was found for porosity, where the densest pillars were printed at 135-150 V and the most porous at 260 V. The maximum experimental deposition speed measured up to 4.1 µm · s−1 at 220 V. Faraday’s law of electrolysis could be used to predict the experimental deposition speed at a potential of 190 V with vexp = 1.8 µm · s−1 and vtheory = 0.8 µm · s−1. The microstructure of the pillars could be improved through lowering the applied voltage. In addition, given that Faraday’s law of electrolysis could predict experimental depositions speeds well, it gives further proof to reduction being the mechanism of deposition.

In this work, various components for low power RF telemetry applications have been investigated. These designed, fabricated and tested devices include radio frequency (RF) micro-electro-mechanical systems (MEMS) switches, single-pole-double-throw (SPDT) RF MEMS switches, nano fabricated capacitors and switching devices, and micromachined microstrip patch antennas.Coplanar waveguide (CPW) RF capacitive switches in shunt and series configuration were designed for high isolation, low insertion loss, and fast switching speed. Switches with > 35 dB isolation, < 0.3 dB insertion loss and switching speeds in the 10's of microseconds were fabricated and measured. These switches were packaged using photo-imagable resists and flip-chip bonding techniques. The MEMS shunt switch topology was also implemented into a single-pole-double-throw (SPDT) design by utilizing two such switches in a series and a shunt configuration, offset by a quarter wavelength section to provide a RF shor t at the input of the shunt switch in the off state. This type of design has the advantage of requiring a simple on-off (0 V and 35 V) bias supply to select the switch state.Also, the use of a focused ion beam (FIB) tool to mill sub-micron gaps in CPW transmission line structures was investigated. Nearly ideal capacitors in the micro- and mm- frequency range with capacitance of 8-12 fF were obtained using this milling technique. The FIB's capability to mill such small gaps at an oblique angle was also utilized to fabricate RF nano switches. These devices were switched with speeds of less than 300 ns with voltages of less than 20 V. Finally, solid state and packaged MEMS switches were integrated into a novel binary amplitude shift keyed (BASK) modulating RF telemetry system to provide the modulation of a redirected 10 GHz continuous wave (CW) signal. A pair of cross-polarized micromachined microstrip patch antennas was used in the system to receive the CW signal and re-transmit th e modulated signal. A transmission range of over 25 m was demonstrated with the solid state switch reflectenna.

Microelectronic devices and systems have been extensively utilized in a variety of radiation environments, ranging from the low-earth orbit to the ground level. A high-energy particle from such an environment may cause voltage/current transients, thereby inducing Single Event Effect (SEE) errors in an Integrated Circuit (IC). Ever since the first SEE error was reported in 1975, this community has made tremendous progress in investigating the mechanisms of SEE and exploring radiation tolerant techniques. However, as the IC technology advances, the existing hardening techniques have been rendered less effective because of the reduced spacing and charge sharing between devices. The Semiconductor Industry Association (SIA) roadmap has identified radiation-induced soft errors as the major threat to the reliable operation of electronic systems in the future. In digital systems, hardening techniques of their core components, such as latches, logic, and clock network, need to be addressed. Two single event tolerant latch designs taking advantage of feedback transistors are presented and evaluated in both single event resilience and overhead. These feedback transistors are turned OFF in the hold mode, thereby yielding a very large resistance. This, in turn, results in a larger feedback delay and higher single event tolerance. On the other hand, these extra transistors are turned ON when the cell is in the write mode. As a result, no significant write delay is introduced. Both designs demonstrate higher upset threshold and lower cross-section when compared to the reference cells. Dynamic logic circuits have intrinsic single event issues in each stage of the operations. The worst case occurs when the output is evaluated logic high, where the pull-up networks are turned OFF. In this case, the circuit fails to recover the output by pulling the output up to the supply rail. A capacitor added to the feedback path increases the node capacitance of the output and the feedback delay, thereby increasing the single event critical charge. Another differential structure that has two differential inputs and outputs eliminates single event upset issues at the expense of an increased number of transistors. Clock networks in advanced technology nodes may cause significant errors in an IC as the devices are more sensitive to single event strikes. Clock mesh is a widely used clocking scheme in a digital system. It was fabricated in a 28nm technology and evaluated through the use of heavy ions and laser irradiation experiments. Superior resistance to radiation strikes was demonstrated during these tests. In addition to mitigating single event issues by using hardened designs, built-in current sensors can be used to detect single event induced currents in the n-well and, if implemented, subsequently execute fault correction actions. These sensors were simulated and fabricated in a 28nm CMOS process. Simulation, as well as, experimental results, substantiates the validity of this sensor design. This manifests itself as an alternative to existing hardening techniques. In conclusion, this work investigates single event effects in digital systems, especially those in deep-submicron or advanced technology nodes. New hardened latch, dynamic logic, clock, and current sensor designs have been presented and evaluated. Through the use of these designs, the single event tolerance of a digital system can be achieved at the expense of varying overhead in terms of area, power, and delay.

Metal thin films deposited on weakly-interacting substrates constitute an essential element of numerous microelectronic, catalytic, and optical devices. However, the natural tendency of metal atoms to agglomerate, upon condensation on a weakly-interacting surface, in dispersed three-dimensional (3D) islands affects negatively the performance of the above-mentioned devices. The aim of this thesis is to investigate one of the mechanisms governing silver (Ag) 3D island growth on weakly-interacting substrates, i.e. the nucleation of a new layer on the island top. Kinetic Monte Carlo (KMC) simulations are employed to calculate the top island-layer critical radius Rc required for nucleating a new layer in the out-of-plane direction. Single-island simulations are performed for growth temperatures T in the range 250 to 500 K and ratios of the pairwise adatom/substrate atom bond strength EB,sub to the corresponding adatom/adatom value EB,film in the range 0.5 to 0.75. We find that for T values below 250 K the islands exhibit a 2D morphology for all EB,sub/EB,film ratios. In contrast, for T values above 300 K there exists a range of relatively small EB,sub/EB,film values, where 2D morphology dominates. To calculate Rc for each island layer as the island shape evolves, a subroutine is developed and implemented in an existing KMC algorithm. Rc values are computed for 3D island growth at EB,sub/EB,film = 0.5 in the T range 300−500 K and the results show that Rc decreases monotonously from 17.3 to 6.0 Å and saturates approximately at 375 K. This trend is opposite to the typical behavior of islands grown under homoepitaxial conditions, for which the enhancement of downward inter-layer diffusion caused by an increase of T leads to lower atomic densities on the top, i.e. to a lower nucleation probability, and thus to an increase of Rc. This work contributes to the understanding of the physical processes that control thin-film morphological evolution; which is paramount for controlling and manipulating film growth for specific applications.

Photodetectors are used in many applications such as digital and thermal cameras or in solar panels. They can also be designed to detect the omnipresent high-energy radiation/particles, and for radiation imaging in biomedical applications. Novel nanostructures offer significant advantages compared to traditional designs for the realization of fast, sensitive, compact and cheap sensors and efficient solar cells. Examples of such nanostructures include quantum dots (QDs), quantum wells (QWs) and NW arrays. This thesis is devoted to experimental investigations of effects of high-energy (1 MeV) protons on the optical and electrical performance of InP/InAsP NW-based QDiscs-in wire photodetectors. The proton-induced degradation of the optical performance has been studied by means of Fourier Transform Infrared (FTIR) photocurrent spectroscopy. The spectrally resolved photocurrent (PC) and current-voltage (I-V) characteristics were measured at low temperature (5 K and 77K) and at room temperature (300K) before and after 1 MeV proton irradiation under vacuum conditions with fluences ranging from 1.0×1012–3.0×1013 cm-2. The particle radiation exposure has been done in the Ion Beam Accelerator at the Department of Nuclear Physics Department at Lund University. Considering both PC and I-V characteristics, it was found that the devices were sensitive to all proton irradiation at all fluences. In general, the PC intensity significantly increased after radiation for all fluences, however, a week after exposure the PC and dark current gradually recovered. At 3×1012 p/cm2 fluence level, it was figured out that photocurrent which attributed to QDiscs disappeared for a couple of days after exposure, however, over time and gradually, those started to manifest again even at low and room temperatures, causing radiation-induced changes in device parameters to be time-dependent; however, it was not recorded any signals related to QDiscs at fluence of 3×1013 p/cm2. Substantial changes in the dark I-V characteristics, as well as increases in the dark current, are observed after irradiation. The influence of proton irradiation on light and dark current characteristics also indicated that NW structures are a good potential candidate for radiation harsh-environment applications. It was also observed a significant increase in dark current after the radiation for all devices, however, by applying the voltage to the photodetectors, the PC and I-V characteristics gradually being to diminish, which may be attributed to an annealing process.

This study aims to examine the throughput of nanoparticles through a Cladophora cellulose based virus removal filter. The effect of Brownian motion and flow velocity on the retention of 5 nm gold nanoparticles, 12.8 nm dextran nanoparticles and 28 nm ΦX174 bacteriophages was examined through MATLAB simulations and filtration experiments. Modeling of Brownian motion at different flow velocities was performed in MATLAB by solving the Langevin equation for particle position and velocity for all three types of particles. The motion of all three particle types was shown to be constrained at local flow velocities of 1∙10-2 m/s or greater. The constraint was greatest for ΦX174 bacteriophages, followed by dextran particles and then gold particles as a result of particle diameter. To verify the effect experimentally, virus removal filters were prepared with a peak pore width of 23 nm. Filtration experiments were performed at different flux values where gold and dextran particles did not exhibit any difference in retention between fluxes. However, a significant amount of gold and dextran particles were removed by the filter despite being smaller than the measured pore size. A decrease in retention with filtrated volume was observed for both particle types. Filtration of ΦX174 bacteriophages exhibited a difference in retention at different fluxes, where all bacteriophages where removed at a higher flux. The results from both simulations and experiments suggest that the retentive mechanism in filtering is more complex than what can be described only by size exclusion sieving, Brownian diffusion and hydrodynamic constraint of particles.

Cellulose, a sustainable raw material derived from nature, can be used for various applications following its functionalization and oxidation. Nanocellulose, inheriting the properties of cellulose, can offer new properties due to nanoscale effects, in terms of high specific surface area and porosity. The oxidation of cellulose can provide more active sites on the cellulose chains, improving its functionalization and broadening applications. Two kinds of oxidation and their corresponding applications are described in this thesis: periodate oxidation and Oxone® oxidation. 2,3-dialdehyde cellulose (DAC) beads were prepared from Cladophora nanocellulose via periodate oxidation, and were further modified with amines via reductive amination. Several diamines were selected as possible crosslinkers to produce porous DAC beads, which showed higher porosity, stability in alkaline solution and enhanced thermal stability. After functionalization of DAC beads with L-cysteine (DAC-LC), thiol, amine and carboxyl groups were introduced into the DAC beads, endowing the DAC-LC beads with high adsorption capacity for palladium. The synthesized DAC-LC beads were character­ized with SEM, FTIR, XPS, TGA, BET and XRD and the palladium adsorption process was investigated. Chitosan was employed as a crosslinker in functionalization of DAC beads (DAC-CS). The conditions for the synthesis of DAC-CS beads were screened and verifying the stability of the beads in alkaline solution. The DAC-CS beads produced were investigated using SEM, FTIR, XPS, TGA and BET, and the adsorption and desorption capacity of Congo red was studied, indicating DAC-CS beads have potential as sorbent. Oxone oxidation of cellulose is a novel one-pot oxidation method in which mainly the hydroxyl groups on C6 are oxidized to produce carboxylic acid groups on the cellulose chains. To increase the efficiency of Oxone oxidation, several reaction parameters were studied. Cellulose pulp and Cladophora nanocellulose were chosen as prototypes to investigate the effects of oxidation, and the physico­chemical properties of the oxidized products were characterized. Cellulose pulp, pretreated with Oxone oxidation, was disintegrated by homogenization to prepare cellulose nanofibers (CNF). The effect of pre­treat­ment on the preparation of CNF was studied, and the results indicated that Oxone oxidation was efficient in the production of CNF.

The goal of this thesis work is to investigate the possibility to grow graphene by Chemical Vapor Deposition (CVD) on copper foil with acetylene as a precursor and varigon (5\% H$_2$ in Ar) as a carrier gas. The possibility of nitrogen doping by ammonia treatment during the growth process is also investigated. The possibility of graphene transfer, with the use of Poly(Methyl Metacrylate) (PMMA), from the copper onto another target substrate, Flourine doped Tin Oxide (FTO), is also explored. The main technique of characterization of the grown and transfered graphene is Raman spectroscopy, a great tool for investigating the number of graphene layers and amount of defects. Other characterization methods used are Scanning Electron Microscopy (SEM) X-ray Photoelectron Spectroscopy (XPS) to investigate morphology and elemental composition, respectively. The result of this thesis study is that graphene growth is entirely possible with acetylene as a precursor, as shown by the Raman spectroscopy, XPS and SEM. The grown graphene has a high quality with few layers and a low number of defects. The ammonia treatment, however, doesn't seem to have an immediate effect on the graphene growth. The XPS data indicates that there are no nitrogen doping in the graphene, though there might be a correlation between the ammonia and the number of layers, but further investigations has to be made. Transfer is also proven possible with the method developed. However, improvements to the transfer method can be done since there are both larger tares, caused by the transfer onto the FTO, as well as microscopic tares, possibly caused by thermal expansion of the PMMA.

Ion exchange reactions between Upsalite, a mesoporous magnesium carbonate, and metal ions of cadmium, lead and nickel have been studied to evaluate the capacities of Upsalite as a water treatment agent. Uptake capacity and reaction kinetics have been evaluated using a batch experiment and atomic absorption spectroscopy. Post reaction materials from the reaction between Upsalite and each of the three metal ions have been investigated with XRD, SEM and TGA in order to determine what species have been formed during the ion exchange.   The maximum uptake capacity of Upsalite was found to be 990 mg/g for cadmium ions and 470 mg/g for nickel ions. The evaluation of the uptake capacity of lead ions in Upsalite was not conclusive but the results indicate a maximum uptake capacity of at least 4400 mg/g. The uptake capacity for lead ions is to high be explained by ion exchange alone and is proposed to be from both ion exchange and adsorption. The reaction between Upsalite and cadmium ions resulted in the formation of crystalline CdCO3 (Otavite) with some parts of MgCO3 and crystalline MgO remaining from the original material. Post reaction materials from the reaction between nickel ions and Upsalite were found to be amorphous and contained both MgCO3 and crystalline MgO. The reaction between Upsalite and lead ions resulted in crystalline hydrocerussite (Pb3(CO3)2(OH)2).

The application of nanowires (NWs) in solar cells (SCs) is of great interest due to their new promising aspects established in nanoelectronics. Semiconductors associated with plasmonic metal nanoparticles (NPs) such as Silver (Ag), Gold (Au) and Copper (Cu), show enhanced performance in solid state light absorbing SCs owing to plasmonic characteristic of noble metal NPs. Plasmonic NPs presented a significant role in development of visible light harvesting for many applications such as photocatalytic materials, photodynamic in Surface Enhanced Raman Spectroscopy (SERS) and photovoltaics (PVs). Integration of plasmonic NPs in semiconductor materials have opened the routes to expand new PV systems with high efficiency light absorption. In this project, we introduce the synthesis ZnO and TiO2 NWs used as N-type semiconducting substrates and various methods for isolating plasmonic metal NPs, which are later deposited on the semiconducting substrates. Vertically aligned ZnO and TiO2 NWs arrays were grown on the fluorine-doped tin oxide (FTO) conductive glass substrates via hydrothermal method at low temperature and the plasmonic NPs were synthesized by wet chemistry procedures and finally decorated on the NW films by using electrophoretic deposition.  The impact of metal NPs loaded on the ZnO and TiO2 NWs substrates was studied by means of UV-vis spectroscopy and Photoluminescence (PL) spectroscopy. The absorbance spectra of individual NPs were recorded. Remarkably, the reflectance spectra of produced samples presented an enhancement in light absorption of the substrates after uptake of NPs on the ZnO and TiO2 NWs. The optical properties of the as grown ZnO NWs films decorated with Ag NPs (I) in direct contact with substrate and (II) in presence of an Al2O3 insulating spacer layer have been investigated. Both systems exhibited an enhancement in the UV band-edge emission from the ZnO when excited at 325 nm. In contrast, the broad bend defect emission of the samples did not have a significant change compare to bare ZnO substrates. The observed results suggested that the ZnO and TiO2 NWs decorated with plasmonic nanoparticles can boost the optical properties of MOs NWs substrates and hence effectively enhance the separation of photoexcited electron-hole pairs and photo-conversion applications.