Ji-Hoon Suh

Multiparameter Sensor Interface Circuit With Integrative Baseline/Offset Compensation by Switched-Capacitor Level Shifting/Balancing

The proposed sensor interface circuit provides an integrative baseline/offset compensation to give higher adaptability and effectiveness for multiparameter sensing microsystems. Capacitive/resistive and voltage type sensors are dealt with and switched-capacitor-based circuits are mostly employed to facilitate integrative baseline/offset cancellation and interface various types of sensors. For integrative signal conditioning, sensor signals are first converted to voltage signals and then given rail-to-rail baseline compensation and fine offset cancellation of 0.7 mV/bit. At the same time, each interface circuit demonstrates a large total conversion gain (C: 194 mV/fF, R: 6260 mV/k

A CMOS low-power polar demodulator for electrical bioimpedance spectroscopy using adaptive self-sampling schemes

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Veri-Pen: A Pen-based Identification Through Natural Biometrics Extraction

, V: 230 V/V) and a coefficient of determination (R2) over 0.998, which indicates a high conversion linearity.

Finger motion detection glove toward human-machine interface

A CMOS integrated low-power polar demodulator for electrical bioimpedance spectroscopy is proposed. This polar demodulator extracts magnitude and phase of tissues impedance. Two adaptive self-sampling schemes, namely zero-time sampling (ZTS) and peak-time sampling (PTS), are proposed to efficiently extract the magnitude of impedance. Since ZTS scheme reuses clock signals used in the XOR-based phase-extracting circuit, low-power consumption is achieved. When ZTS scheme is used, magnitude error increases as frequency of the injected sinusoidal signal increases. Instead of ZTS scheme, PTS scheme is used when the signal above 100 kHz is injected. Targeting 1-kHz to 2.048-MHz frequency range, the proposed demodulator designed in a 0.25-im CMOS process consumes 10.3 mW at its maximum with magnitude and phase errors of 1.0% and 1.3°, respectively.

Multi sensor voltage signal conditioner with adaptive level shift and DC offset calibration on a single chip

As we live in the Internet age, we face high threats of data leakage, identity theft, and inconvenience over authenticating ourselves online. Safe and simple digital identification is crucial in the digital realm. In order to solve the above issues, a mediating digital assistive device could possibly act between the user and computer system in order to replace the current identification system. In this paper I present Veri-Pen, a stylus that provides digital identification through the natural extraction of a signature and fingerprint. The proposed concept aims to deliver simple and secure pen-based online identification. The prototype, built upon user case studies, was evaluated in a simulated scenario of digital authentication in comparison to conventional ID-password identification. The user evaluation confirmed that the pen-based identification tool with biometrics delivers a simple and trustworthy experience to users during the procedure of authentication.

Small size 433 MHz On-off keying transceiver IC for sensor application

Finger motion capturing systems have a wide variety of applications such as telerobotics, rehabilitation, and avatar control. While commercial devices are too costly, studies on such systems are either impractical to use or have speed limitations. This paper proposes a practical version of the glove-based finger motion capturing system. This system can achieve a capture speed high enough to represent smooth and swift finger motions with considerably low cost. The system provides a speed of 54 Hz for 14 channels with their signal conditioning circuits and flexible strain sensors. In addition, the system has one-touch calibration mode for baseline cancellation, which makes it user-friendly more.

Modeling of Human Genetic Diseases Via Cellular Reprogramming

This paper presents an adaptive signal conditioning method for multi sensors with initial voltage setting, offset calibration and signal amplification. The initial voltage setting process to VDD/2 (600 mV) by level shifters is implemented for adapting various sensor signals, even when the signals frequency is of several Hz or its initial voltage is of several mV. Offset calibration is implemented inside a programmable gain amplifier to compensate initial voltage setting error. The architecture can amplify various types of sensor signals below supply voltage (1.2 V) without coupling capacitors.

3D printing of multiaxial force sensors using carbon nanotube (CNT)/thermoplastic polyurethane (TPU) filaments

In order to make wireless sensor nodes, low power consumption and low cost RF transceiver are required. In this work, a 433 MHz On-Off keying transceiver is designed and simulated with Dong-bu 0.11 μm CMOS process. For high data rate and power efficiency, digital pulse shaping is adopted. For small size and low power, the receiver is designed using the digital pulse-shaped signal for demodulation. The chip size is 180 × 180 μm2 without pads.

Fully integrated and portable semiconductor-type multi-gas sensing module for IoT applications

different in the clinical studies between mouse and human. In fact, many drugs that have been proved to be effective in mouse models do not work well in the patients. Thus, development of new systems for realizing disease-specific phenotypes is needed to explore fundamental mechanisms of various human diseases. In this context, human embryonic stem cells (hESCs) first established by Thomson et al. and induced pluripotent stem cells (iPSCs) first developed by Takahashi and Yamanaka have been highlighted in the research of human diseases at the molecular and cellular levels as well as in the cell replacement therapy. Also, human ESCs and iPSCs can be employed to screen new drugs and to test drug toxicity in vitro. In this review, we are focusing on the concept of cellular reprogramming and in vitro disease modeling using iPSCs, especially for genetic diseases. Also, we briefly describe current breakthroughs and prospects of the iPSC research. Modeling of Human Genetic Diseases Via Cellular Reprogramming