The history of innovation is full of humans looking towards nature for inspiration and answers to complicated technical challenges. Biomimicry has led to many of our civilization's greatest innovations, such as the Wright brothers studying birds for inspiration in creating the airplane or Japanese engineers mimicking the Kingfisher to create their bullet train. 

A few examples of biomimicry. Image used courtesy of Mibelle Biochemistry

Last week, researchers at TU Delft continued this tradition of biomimicry, this time taking inspiration from spider webs to develop new quantum sensors that can operate at room temperature. 

In this article, we'll look into the research presented and the impressive results of the new sensor.

Challenges with Quantum Sensing 

Today, interest in the quantum world has been steadily increasing day by day. Between astrophysics research and quantum computers, engineers worldwide have found themselves in need of high-precision sensors that can work on the quantum level. 

However, sensing at the quantum level poses a significant challenge: achieving precision and resolution is difficult.

The need for cryogenic quantum computing significantly limits quantum hardware. Image used courtesy of Microsoft

When measuring signals on a quantum level, the amplitude of these signals is extremely small. The signals are so small, in fact, that the effects of environmental noise have a significant influence on the overall amplitude of the signal. This influence has fundamentally limited the ability to create reliable quantum sensors, as it becomes complicated to differentiate between our desired signal and noise. 

One way to overcome this, quantum hardware is kept as close to absolute zero (0K) as possible. Keeping the hardware in these energyless environments removes the influence of external noise but also makes quantum hardware extremely expensive and limited. 

Spiderwebs Inspire Quantum Sensing Innovations

Trying to solve this issue, the researchers at TU Delft found inspiration from an unlikely source: spiderwebs. 

A critical feature of a spiderweb is that they are intrinsically very good vibration detectors, allowing the spider to measure the vibrations of their prey within their web without the effects of outside vibrations like the wind. 

When viewing this analogously to the quantum sensing problem, it turns out that spiderwebs could become a remarkable solution. Unfortunately for the researchers, they were not experts in spider webs' intricacies and inner mechanisms.

The sensor’s proposed spider web geometry. Image used courtesy of Shin et al

As the researchers explain in their paper, they tackled this problem using Bayesian optimization, a machine learning (ML) technique for global optimization of black-box functions. 

Essentially, the researchers fed their ML algorithm with 150 spider web designs and told it to return the design that would best induce soft clamping with a compact design and achieve high-quality factors in the low-frequency regime for a given resonator size. 

The resulting solution was unexpectedly simple, consisting of six strings in a simple pattern. The researchers then took this pattern and implemented it on a microchip using silicon nitride nanostructures. 

When testing their new sensor, the results were incredible, showing an extremely high-quality factor and record-breaking isolated vibration at room temperature. Most importantly, their new solution benefits from a novel vibration mode, not a new and more challenging fabrication technique. 

Future Work

The researchers feel that their new mechanical resonator could significantly impact many fields that rely on quantum sensing. 

By enabling high-quality factor, high isolation sensors that work at room temperature, they hope to benefit fields like astrophysics research and the quantum internet.

Featured image used courtesy of Frank Auperlé and TU Delft

Interested in other quantum sensor work? Read on in the articles down below.

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