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Non-volatile radio-frequency (RF) switches based on hexagonal boron nitride (hBN) are realized for the first time with low insertion loss (≤ 0.2 dB) and high isolation (≥ 15 dB) up to 110 GHz. Crystalline hBN enables the thinnest RF switch device with a single monolayer (~0.33 nm) as the memory layer owing to its robust layered structure. It affords ~20 dBm power handling, 10 dB higher compared to MoS 2 switches due to its wider bandgap (~6 eV). Importantly, operating frequencies cover the RF, 5G, and mm-wave bands, making this a promising low-power switch for diverse communication and connectivity front-end systems. Compared to other switch technologies based on MEMS, memristor, and phase-change memory (PCM), hBN switches offer a promising combination of non-volatility, nanosecond switching, power handling, high figure-of-merit cutoff frequency (43 THz), and heater-less ambient integration. Our pioneering work suggests that atomically-thin nanomaterials can be good device candidates for 5G and beyond. 

Electrooculography (EOG) is a method to record the electrical potential between the cornea and the retina of human eyes. Despite many applications of EOG in both research and medical diagnosis for many decades, state-of-the-art EOG sensors are still bulky, stiff, and uncomfortable to wear. Since EOG has to be measured around the eye, a prominent area for appearance with delicate skin, mechanically and optically imperceptible EOG sensors are highly desirable. Here, we report an imperceptible EOG sensor system based on noninvasive graphene electronic tattoos (GET), which are ultrathin, ultrasoft, transparent, and breathable. The GET EOG sensors can be easily laminated around the eyes without using any adhesives and they impose no constraint on blinking or facial expressions. High-precision EOG with an angular resolution of 4° of eye movement can be recorded by the GET EOG and eye movement can be accurately interpreted. Imperceptible GET EOG sensors have been successfully applied for human–robot interface (HRI). To demonstrate the functionality of GET EOG sensors for HRI, we connected GET EOG sensors to a wireless transmitter attached to the collar such that we can use eyeball movements to wirelessly control a quadcopter in real time.