online desk | 02 April 2018 | 1:59 pm
Researchers are developing atomically thin “drumheads”, which are tens of trillions of times thinner than the human eardrum, and will provide cat-like hearing abilities to humans.
According to the results of the ongoing research published in the journal Science Advances, these “drumheads” would be able to receive and transmit signals across a radio frequency range far greater than what we can hear with the human ear.
Researchers at Case Western Reserve University in the US said that they achieved this cat-like ‘hearing’ with a device that is tens of trillions times (10 followed by 13 zeros) smaller in volume and 100,000 times thinner than the human eardrum.
“We need transducers that can handle signals without losing or compromising information at both the ‘signal ceiling’ (the highest level of an undistorted signal) and the ‘noise floor’ (the lowest detectable level),” said corresponding author on a paper Philip Feng.
They constructed the device by exfoliating individual atomic layers from the bulk semiconductor crystal and using a combination of nanofabrication and micromanipulation techniques to suspend the atomic layers over micro-cavities pre-defined on a silicon wafer and then making electrical contacts to the devices.
“What we’ve done here is to show that some ultimately miniaturized, atomically thin electromechanical drumhead resonators can offer remarkably broad dynamic range, up to ~110dB, at radio frequencies (RF) up to over 120MHz,” Feng said.
“These dynamic ranges at RF are comparable to the broad dynamic range of human hearing capability in the audio bands.”
Human eardrums normally have dynamic range of about 60 to 100dB in the range of 10Hz to 10kHz, and our hearing quickly decreases outside this frequency range.
Other animals, such as the common house cat or beluga whale, can have comparable or even wider dynamic ranges in higher frequency bands.
The study also revealed that these incredibly small drumheads only need picoWatt up to nanoWatt level of RF power to sustain their high frequency oscillations.
The advances would likely contribute to making the next-generation of ultralow-power communications and sensory devices smaller and with greater detection and tuning ranges.