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Resistive switching (RS) memristor has been widely used in the in-memory computation systems. Due to the strong information processing capability and low area cost of the ternary logic, the development of the three-state RS memristor was promoted. Here, we demonstrate a three-state RS phenomenon on Pt/BiFeO3/SrRuO3 structure. After applying a positive voltage to the thin film for a period, an abrupt RS effect occurs, where the three-state RS behavior can be obtained. By analyzing the conduction mechanisms of the current-voltage curves and the behavior of the capacitance-voltage curves, the three-state storage capability of the memristor can be ascribed to the movement of oxygen vacancies and the trapping/detrapping of charge carriers at the interface. The ternary OR logic gate was also designed with three steps by using only one memristor.

A method for inverse determination of the coefficients of thermal expansion of an electronic device that is composed of multiple materials, i.e. dissimilar materials, is proposed. The virtual fields method is applied for obtaining the coefficients of thermal expansion. Appropriate virtual displacement fields have been automatically obtained instead of using any arbitrary virtual displacement. This leads to an accurate and effective determination of the coefficient of thermal expansion. Full-field displacement distributions measured by digital image correlation are used as input for the inverse analysis. The validity of the proposed method has been demonstrated by measuring samples made of various materials. Furthermore, the proposed method is applied to samples simulating electronic devices with and without constraints on the boundary. Results show that the coefficients of thermal expansion of an object composed of dissimilar materials are obtained properly. The proposed method is expected to be used for determining the coefficients of thermal expansion of actual electronic devices.

Wearabl smart devices have become an important method to monitor people’s health. This research work aims to offer a relatively optimum solution to amplify the biomedical signal in the case of wearable devices. This is done by using the single-stage amplifier and Operational Transimpedance Amplifier (OTA) stage. The OTA stage uses a typical 2-stage amplifier topology, with first-stage differential pair, second stage a common source to provide high-gain. Simulation results showed that the amplifier has a differential gain of 40.04dB, a total integrated input-referred noise of 3.59uVrms, a total power consumption of 1.44uW, a NEF of 21 and a CMRR of 82 dB. In conclusion, the results verify the single-stage amplifier topology is useful and satisfy the low-power requirement.