Tuesday, April 18, 2023
12:00 PM - 1:00 PM
Trafon Center 310
Title: [2]Rotaxane as a switch for molecular electronic memory application: A molecular dynamics study
Abstract: As VLSI technology is shifting from microelectronics to the nanoelectronics era, bi-stable [2]rotaxane emerges as a promising candidate for molecular electronics. A typical voltage-driven [2]rotaxane consists of a cyclobis-(paraquat-p-phenylene) macrocycle encircling a dumbbell shape molecular chain and moving between two stations on the chain: tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP). As a molecular switch, the macrocycle can move reversibly between two stations along its axis with appropriate driving voltage, resulting in two stable molecular conformational states with distinct high and low resistance. This makes it a well-suited candidate to represent binary states (“0” and “1”) for digital electronics. In this work, we performed a molecular simulation to investigate the switching mechanism of [2]rotaxane molecule. We used distance and angle variables to characterize the movement of the macrocycle along the chain and compared the switching behavior of [2]rotaxane in water, ethanol, dimethyl ether, and vacuum. The results show that the solvent environment plays an important role in the switching characteristics of [2]rotaxane molecule. The switching of [2]rotaxane is stable, controllable, reversible and repeatable. We also looked into the potential failure mechanism of the [2]rotaxane, which could shed light on the fault model, testing and reliability enhancement of [2] rotaxane-based molecular electronics. Our simulation results support that [2]rotaxane molecules possess the potential to be used for molecular memory and logic applications.
