Jeffrey B.W. Soon

Bio: Jeffrey B.W. Soon is an academic researcher from Agency for Science, Technology and Research. The author has contributed to research in topics: Resonator & Piezoelectricity. The author has an hindex of 6, co-authored 17 publications receiving 163 citations. Previous affiliations of Jeffrey B.W. Soon include Singapore Science Park.

From chip-in-a-lab to lab-on-a-chip: towards a single handheld electronic system for multiple application-specific lab-on-a-chip (ASLOC)

Abstract: We present a portable, battery-operated and application-specific lab-on-a-chip (ASLOC) system that can be easily configured for a wide range of lab-on-a-chip applications. It is based on multiplexed electrical current detection that serves as the sensing system. We demonstrate different configurations to perform most detection schemes currently in use in LOC systems, including some of the most advanced such as nanowire-based biosensing, surface plasmon resonance sensing, electrochemical detection and real-time PCR. The complete system is controlled by a single chip and the collected information is stored in situ, with the option of transferring the data to an external display by using a USB interface. In addition to providing a framework for truly portable real-life developments of LOC systems, we envisage that this system will have a significant impact on education, especially since it can easily demonstrate the benefits of integrated microanalytical systems.

Super High Frequency Aluminum Nitride Two-Dimensional-Mode Resonators With $k_{t}^{2}$ Exceeding 4.9%

Abstract: In this work we demonstrate high values of electromechanical coupling coefficient ( $k_{t}^{2}$ ) exceeding 4.9% in 1- $\mu \text {m}$ thick Aluminum Nitride (AlN) two-dimensional-mode resonators (2DMRs) operating around 3.2 GHz. Such a high $k_{t}^{2}$ -value, which is attained thanks to the transduction of the resonators through both the $d_{33}$ and $d_{31}$ piezoelectric coefficients of AlN, enables low-power oscillators and low insertion-loss filters, operating in the Super-High-Frequency (SHF) range.

Piezoelectric ALN MEMS resonators with high coupling coefficient

Abstract: Piezoelectric AlN resonators with novel checker-patterned electrode architecture are reported in this paper. An array of interdigitated electrodes is used to excite two-dimensional plate acoustic waves within a thin piezoelectric layer. The resonant frequency can be changed by adjusting the size of the electrode fingers and hence resonators with multiple frequencies can be fabricated on a single wafer. A high coupling coefficient of 3.95% has been measured for one of the checker-mode resonators. A comparison of measured S21 plots of a checker-mode resonator and a contour-mode resonator with similar resonant frequency shows that checker mode is highly specific over a large frequency range.

Vertical silicon nano-pillar for non-volatile memory

Abstract: NanoElectroMechanical (NEM) switches have been proposed for non-volatile memory applications, but low device density remains a key challenge for horizontal switches. This paper presents a resistive, vertically oriented NanoElectroMechanical (NEM) nano-pillar cantilever switch made of mono-crystaline silicon, with a cell size of 8F2. Using a top-down CMOS-compatible process requiring two lithography masks, nano-pillar switches with a height of 500nm, tip thickness of 35nm, and 25nm air gap are fabricated.

Aluminum scandium nitride thin-film bulk acoustic resonators for 5G wideband applications

Abstract: Abstract Bulk acoustic wave (BAW) filters have been extensively used in consumer products for mobile communication systems due to their high performance and standard complementary metal-oxide-semiconductor (CMOS) compatible integration process. However, it is challenging for a traditional aluminum nitride (AlN)-based BAW filter to meet several allocated 5G bands with more than a 5% fractional bandwidth via an acoustic-only approach. In this work, we propose an Al 0.8 Sc 0.2 N-based film bulk acoustic wave resonator (FBAR) for the design of radio frequency (RF) filters. By taking advantage of a high-quality Al 0.8 Sc 0.2 N thin film, the fabricated resonators demonstrate a large K eff 2 of 14.5% and an excellent figure of merit (FOM) up to 62. The temperature coefficient of frequency (TCF) of the proposed resonator is measured to be −19.2 ppm/°C, indicating excellent temperature stability. The fabricated filter has a center frequency of 4.24 GHz, a −3 dB bandwidth of 215 MHz, a small insertion loss (IL) of 1.881 dB, and a rejection >32 dB. This work paves the way for the realization of wideband acoustic filters operating in the 5G band.

Recent advances in nanoplasmonic biosensors: applications and lab-on-a-chip integration

Abstract: Motivated by the recent progress in the nanofabrication field and the increasing demand for cost--effective, portable, and easy-to-use point-of-care platforms, localized surface plasmon resonance (LSPR) biosensors have been subjected to a great scientific interest in the last few years. The progress observed in the research of this nanoplasmonic technology is remarkable not only from a nanostructure fabrication point of view but also in the complete development and integration of operative devices and their application. The potential benefits that LSPR biosensors can offer, such as sensor miniaturization, multiplexing opportunities, and enhanced performances, have quickly positioned them as an interesting candidate in the design of lab-on-a-chip (LOC) optical biosensor platforms. This review covers specifically the most significant achievements that occurred in recent years towards the integration of this technology in compact devices, with views of obtaining LOC devices. We also discuss the most relevant examples of the use of the nanoplasmonic biosensors for real bioanalytical and clinical applications from assay development and validation to the identification of the implications, requirements, and challenges to be surpassed to achieve fully operative devices.

LAMP-on-a-chip: Revising microfluidic platforms for loop-mediated DNA amplification

Abstract: Nucleic acid amplification for the detection of infectious diseases, food pathogens, or assessment of genetic disorders require a laboratory setting with specialized equipment and technical expertise. Isothermal deoxyribonucleic acid amplification methods, such as loop-mediated isothermal amplification (LAMP), exhibit characteristics ideal for point-of-care (POC) applications, since their instrumentation is simpler in comparison with the standard method of polymerase chain reaction. Other key advantages of LAMP are robustness and the production of pyrophosphate in the presence of the target gene, enabling to detect the reaction products using the naked eye. Polymerase inhibitors, presented in clinical samples, do not affect the amplification process, making LAMP suitable for a simple sample-to-answer diagnostic systems with simplified sample preparation. In this review, we discuss the trends in miniaturized LAMP techniques, such as microfluidic, paper-based, and digital with their advantages and disadvantages, especially for POC applications alongside our opinion of the future development of miniaturized LAMP.

Droplet microfluidics in (bio)chemical analysis

Abstract: Droplet microfluidics may soon change the paradigm of performing chemical analyses and related instrumentation. It can improve not only the analysis scale, possibility for sensitivity improvement, and reduced consumption of chemical and biological reagents, but also the speed of performing a variety of unit operations. At present, microfluidic platforms can reproducibly generate monodisperse droplet populations at kHz or higher rates with droplet sizes suitable for high-throughput experiments, single-cell detection or even single molecule analysis. In addition to being used as microreactors with volume in the micro- to femtoliter range, droplet based systems have also been used to directly synthesize particles and encapsulate biological entities for biomedicine and biotechnology applications. This minireview summarizes various droplet microfluidics operations and applications for (bio)chemical assays described in the literature during the past few years.