The environment in which humans live has only one atmospheric pressure, while extreme environments such as the depths of the ocean are ultra-high-pressure environments. Under extreme environments, traditional pressure sensors are limited by various limitations such as processing technology and material properties. There are certain limitations in sensitivity and pressure measurement limits. For example, the current pressure measurement limit that traditional pressure sensors can reach is about one thousand atmospheres. Detection in more extreme areas will not be possible due to insufficient measurement limits and accuracy of the sensor.
Juana Xia’s research further leads to opportunities for building new ultrahigh-pressure sensors. Existing pressure sensors, like capacitive or piezoresistive sensors based on piezoelectric membranes, are often limited by the tradeoff between sensitivity/responsivity and dynamic range: thinner membranes are more sensitive, but would collapse at elevated pressure. Thicker membranes might withstand higher pressure, but are much less responsive to pressure change. In contrast, 2D structures are atomically thin, and can withstand very high pressure (over a million-atmosphere pressure) without damage, while still responding to pressure change in terms of electronic structure. Therefore, 2D materials can potentially lead to future sensors that can operate up to 1011 Pa pressure.
Besides using pressure, Xia has explored a number of other schemes for tuning interlayer coupling in 2D structures. For example, harnessing the unique degree of freedom “stacking order," she made important breakthroughs in high-throughput characterizing of sample stacking angles (improving the measurement throughput by order-of-magnitudes), and thus further demonstrated novel spin-valley polarization and optoelectronic devices in 2D semiconducting homojunctions. By exploiting tools such as intercalation and strain engineering, she also realized retainable tuning in 2D semiconductors, and thus revealed the underlying physical processes in structural evolution and phase transition in 2D materials.
Xia is an outstanding female scientist who has set a role model for young women who love science. She is rooted in western China and works tirelessly in the field of two-dimensional materials, contributing to mankind's further exploration and understanding of the physical science under extreme conditions.
