Microfluidic technology has important applications in Point-of-Care (POC) diagnostics, and in high throughput screening and sequencing through the introduction of small, automated and portable microfluidic devices commonly known as Lab-on-Chip (LOC) devices, and Micro Total Analysis System (µTAS). These devices can perform biochemical and fluidic assays in automated fashion, using smaller amounts of samples and in faster periods of time when compared to traditional methods. However, LOC devices require the integration of active fluidic components as well as a wide array of sensors and actuators on the chip, which has presented a significant challenge in the traditional methods of fabricating microfluidics. In this dissertation, the use of the Printed Circuit Board (PCB) is proposed as a heterogeneous integration platform for microfluidic LOC devices. A novel heterogeneous integration architecture is demonstrated that enables the integration of microfluidics, electronics and optics on PCBs, and promotes standardized, scaled and cost effective fabrication of LOC devices. The fabrication and integration processes are described by demonstrating several microfluidic LOC devices built on PCBs, and integrated with key LOC functions on the chip, such as sample preparation, analyte extraction, and optical detection.

Laser acupuncture has long been regarded as an effective and minimally intrusive practice for regulating body dysfunctions. However, critical gaps, notably unwearable devices, lack of consensus on treatment protocols, and extensive training required for practitioners impede the ability to introduce laser acupuncture therapy pervasively into telemedicine scenarios. A wearable modality used for standardized laser acupuncture therapy with proper objective feedback would embody the potential to revolutionize how we interact with and manage our health and well-being.This dissertation reviews prevalent laser parameters in laser acupuncture and focuses on developing the AcuHealth system, a wearable cyber-physical system for standard auricular laser acupuncture. The dissertation also encompasses a randomized-controlled trial conducted to evaluate the effectiveness of the AcuHealth V1.0 system in administering auricular laser acupuncture to parents of children undergoing outpatient surgery, thereby assessing its practical feasibility on anxiety mitigation. Furthermore, an advanced version of the AcuHealth system is proposed, enhanced with automated acupoint localization algorithms and laser steering actuators to fully bridge the gaps in current laser acupuncture practices and realize automated and personalized laser acupuncture therapy in telemedicine scenarios.

In this dissertation, we have explored the use of a highly anisotropic film, porous anodic aluminum oxide (AAO) for electronic and MEMS applications. In the first part, AAO templates integrated with ferromagnetic material were studied for spiral inductors as a magnetic core. In the second part, the applications of AAO as a structure material, a mold for electroforming, and a sacrificial layer for MEMS applications were demonstrated.

There is a strong demand for high performance and quality spiral inductors for radio frequency integrated circuits (RFIC). For this purpose, ferromagnetic materials are integrated into the spiral inductors to improve their performance and miniaturize their size. However, spiral inductors with ferromagnetic cores suffer from poor performance at high frequencies due to ferromagnetic resonance effect and eddy current loss occurrence in the layer of ferromagnetic materials. Since AAO templates are self-laminated and patterned, these drawbacks are solved by integration of ferromagnetic materials into the nanopores of AAO templates. By using nickel electroplated AAO templates as a magnetic core, we presented 21% enhancement of inductance value at 5 GHz with a quality factor of 14.48.

High precision, high aspect ratio structures are needed for a variety of microelectromechanical systems (MEMS) applications. The most common technology for producing high aspect ratio structures for MEMS is deep reactive ion etching (DRIE). Despite the successes of the DRIE process for MEMS applications, it has several significant shortcomings which limit its adoption for many microstructure applications.

The DRIE process is expensive, time consuming, requiring expensive dedicated etching equipment, and primarily useful for etching structures in silicon, making it unlikely to be used for non-silicon applications. Other technologies, such as LIGA and SU-8 are highly specialized, and while they can be used for making simple structures, they are generally not useful for producing MEMS-like structures. Since AAO templates are highly anisotropic and can be prepared at various thicknesses, deep vertical structures with high aspect ratios can be formed by a simple low cost wet etching process. Various types of MEMS structures were fabricated by using this technique.

The nanometer-range Indium Arsenide Composite Channel (IACC) High Electron Mobility Transistors (HEMTs) are fabricated on 100 mm Indium Phosphide (InP) substrates. This technology offers the best performance for low-noise and high-frequency, space and military applications. Typical failure mechanisms are observed in III-V HEMT technologies, including gate sinking and oxidation. Experiments were conducted to determine if these failure mechanisms degrade the IACC HEMTs after updating the new HEMT. The experiments conducted were life tests completed at accelerated temperatures and biases with a thin Si3N4 passivation layer; the devices’ electrical characteristics were measured at each stress interval. The failure mechanisms examined within this dissertation include: gate sinking, which is the interdiffusion of the metal gate into the semiconductor. Therefore, a temperature stress was done to initiate the mechanism; oxidation is the migration of oxygen atoms into materials are induced by a high electric field and high temperature. The Si3N4 passivation thickness was then increased to determine if the degradation of the electrical parameters could be decreased. Four HEMTs were placed on a Low-Noise Amplifier (LNA) circuit, therefore, an additional LNA assessment was completed to determine which device degraded and where the defect might be located; the Low-Noise Amplifier (LNA) Circuit assessment determines the limiting HEMT in the LNA circuit. Since many of the known III-V semiconductor failure mechanisms physically degrade or damage HEMTs, cross-sections are important to prepare to detect these mechanisms. Advanced microscopy techniques, with sub-nanometer resolutions, examined physical characteristics of the HEMT at the atomic scale. Each device was cross-sectioned with a Focused Ion Beam/Scanning Electron Microscope (FIB/SEM) and polished with a Nanomill to about 100 nm thickness at the gate fingers to look for the failure mechanisms. The Scanning Transmission Electron Microscope (STEM) along with Energy Dispersive Spectroscopy (EDS) was then used to see the oxygen in the titanium gate layer and no gate sinking. TCAD modeling simulations were used to verify these results and show that the Schottky barrier height changes and the oxygen diffuses faster through the titanium gate layer due to the electric-field increase.

According to the literatures and our previous publication, recent researches on bandpass filter design often puts emphasis on configurable center frequency (fc), controllable bandwidth, and multiple moveable notches. However, such designs are frequently inflicted by unwanted stopband transmissions. When such a transmission is too close to the center frequency, it will impact the receiver performance. Especially for the modern receiving modules, unwanted transmission may cause de-sense in other bands.

Proposed novel substrate integrated waveguide (SIW) short-circuited coax (SCC) filter demonstrates a passband that has transmission zeros on both the upper and the lower stopbands; therefore, rejections near the passband are greatly improved. Such a filter is inherent with good out-of-band rejection up to three times of the fc. In the design, there are four signal paths from the input port to the output port. The signal routings are done by the slotlines on the top metal layer. Two sets of surface-mount capacitors on the bottom metal layer are used to configure the passband, one set is frequency control capacitors (CFreq) while another set is enhance coupling capacitors (CE). The center frequency of the passband can be determined by CFreq, and the transmission zero on the lower-end can be tuned by CE. The phase delay of the signal routings are investigated individually as a way to explain the generation of the transmission zeros around the passband.

To minimize the discrepancy between the ideal simulation and the realization, the structure of the simulated filter from ANSYS High Frequency Structure Simulator (HFSS) can be exported as a touchstone file. Such a file can be later connected to the capacitors’ two-port touchstone files provided by the vendor in the Advanced Design System (ADS) circuit simulator. Thereby, simulation results including all the parasitic components from the capacitor can be emulated the real-world measurements.

Due to the fact that the parasitic inductance of the capacitor can trigger resonance above the passband, and degrade the stopband rejection significantly. Multiple parallel capacitors are used to replace the single standalone capacitor in each capacitive loading, such that the equivalent parasitic resistance and the parasitic inductance are further reduced. As a result, inband loss as well as stopband spurs can be minimized. The result of proposed filter design demonstrates a targeted passband centered at 4.84 GHz, with better than 30-dB rejection up to 3fc, and has insertion loss of 2.11 dB and the 3-dB bandwidth of 0.46 GHz.