Lab On a Chip System for Size-Based Gold and Polymer Nanoparticle Separation

Despite the increasing demand for nanoscale biomolecule analysis for point-of-care (POC) application, nanoparticle separation remains a challenge in many applications due to huge sample loss during separation, low throughput, large scale input materials requirement, and sophisticated technologies. As the separation efficiency may affect the subsequent sample processing and analysis, a robust and reliable size-based separation technique is necessary. This study presents a lab on a chip system to enhance the separation performance by using rapid and straightforward polymer prototyping. In particular, the system consists of a microfluidic network with embedded membrane filters with different pore size cut-offs and an ultrasonic transmitter for acoustic agitation. Using the novel system, we successfully demonstrate the fractionation of 15 nm Au NP from polydisperse nanoparticle solution in the presence of ultrasonic wave (28-40 kHz) generated by the transducer incorporated with the microfluidic system during the separation. Ultrasonic irradiation helps in preventing cake formation and reversing the fouling process by acoustic agitation. The suggested system significantly increases the flow rate during the separation process and improves the recovery of target size nanoparticles. This microfluidic platform is expected to serve as a powerful tool for sample preparation and analytical methodology in POC applications.

A New Approach to Power Efficiency Improvement of Ultrasonic Transmitters via a Dynamic Bias Technique

To obtain a high-quality signal from an ultrasound system through the transmitter, it is necessary to achieve an appropriate operating point of the power amplifier in the ultrasonic transmitter by applying high static bias voltage. However, the power amplifier needs to be operated at low bias voltage, because a power amplifier operating at high bias voltage may consume a large amount of power and increase the temperature of the active devices, worsening the signal characteristics of the ultrasound systems. Therefore, we propose a new method of increasing the bias voltage for a specific period to solve this problem by reducing the output signal distortion of the power amplifier and decreasing the load on the active device. To compare the performance of the proposed method, we measured and compared the signals of the amplifier with the proposed technique and the amplifier only. Notably, improvement was achieved with 11.1% of the power added efficiency and 3.23% of the total harmonic distortion (THD). Additionally, the echo signal generated by the ultrasonic transducer was improved by 2.73 dB of amplitude and 0.028% of THD under the conditions of an input signal of 10 mW. Therefore, the proposed method could be useful for improving ultrasonic transmitter performance using the developed technique.

Klasifikasi Tingkat Kemurnian Bahan Bakar Minyak Berdasarkan Cepat Rambat Gelombang Menggunakan Algoritma K-Nearest Neighbor

The need for fuel oil has increased along with the increase of population, the number of vehicles and industries. An increase in demand for fuel oil is used by some people to make a profit by selling mixed fuel oil at the same price as the price set by the government. The purpose of this study is to create a prototype device that can characterize the type of fuel oil and create a classification system to determine the level of fuel purity with 40 kHz ultrasonic waves based on the parameters of wave velocity using the K-Nearest Neighbor (KNN) algorithm.This device works by using a 40 kHz ultrasonic wave that is connected to an ultrasonic transmitter. The propagated wave will be received by the ultrasonic receiver. The wave received by the receiver will be amplified and connected to the comparator circuit so that it can be processed by a microcontroller. Data obtained using this tool are wave travel time, wave velocity, density, and attenuation. The data used for classification systems using the KNN algorithm is wave velocity.Classification using the KNN algorithm can identify the level of fuel purity based on the parameters of the wave velocity obtained from ultrasonic wave gauges with an accuracy of 72.50%. Wave velocity which is measured using ultrasonic waves is directly proportional to the actual speed with the largest percentage of deviations that is 0.34%.

Perancangan Alat Ukur Massa Jenis Zat Cair Menggunakan Cepat Rambat Gelombang Ultrasonik

Density is a measure of the mass of volume unity. How to measure density in general by measuring the weight and dividing it by the volume of liquid, so in this way the measurement is not. Measurement of the density of the liquid based on the ultrasonic velocity becomes an alternative so that the measurement can be done directly, accurately, practically, and easily.Ultrasonic velocity becomes the variable to determine the density of the liquid. Time synchronization begins when the ultrasonic transmitter emits ultrasonic and is terminated when the receiver receives ultrasonic. The discrete ultrasonic wave transmission method is performed when the ultrasonic receiver receives transmittance from the ultrasonic transmitter then the 40KHz signal pulse is stopped and ultrasonic transmission is repeated up to 10 times the measurement data.From this study obtained some conclusions. Ultrasonic velocity is influenced by the viscosity of the liquid, ultrasonic velocity through 1394m / s aquades, ultrasonic velocity through cooking oil 1387m / s, ultrasonic velocity through liquid soap 1175m / s, ultrasonic velocity through liquid soap solution 40% 1317m / s , Ultrasonic velocity through liquid soap solution 70% 1257m / s, velocity measurement deviation of 0.43% and 0.01% density calculation type.