What characteristics might make up an ideal base sensing material? Many believe one of the pre-requisites is surface to volume ratio – how much of the material’s mass is available to be exposed to the desired sensing area. The consensus seems to be thinner is better. How about conductivity? Once the signal is sensed, at what speed can that signal be completely transmitted? Then, it would be preferred if this base sensing material were also strong, flexible, transparent, a barrier material and available in abundance.
Only a decade ago, the opportunity to discover such a material that fits this description might have sounded like a pipe-dream or been something of a leap too far into the future. However, this future is now here, with a material proven to work and currently being designed and tested for many advanced sensing applications. The base sensing material in question is pure carbon in the form of monolayer graphene and the science for graphene sensors is well advanced. Only engineering work remains for this material to be applied to many micro sensing schemas across industry.
“Graphene is an ideal material for sensors. Every atom in graphene is exposed to its environment allowing it to sense changes in its surroundings. For chemical sensors, the goal is to be able to detect just one molecule of a potentially dangerous or indicative substance. Graphene now allows for the creation of micrometer-size sensors capable of detecting individual events on a molecular level”. University of Manchester website, “Graphene, Learn, Applications, Sensors”
Performance Key of Graphene Sensors
Coming in at only a single atom in thickness, advanced graphene sensors can allow the detection and transmission of the signal of any perturbation in its electron flow, with a capability currently unmatched. No other known base material can measure up to the sensing performance, ease of handling and immediate abundance of the monolayer carbon structure that a graphene sensor is comprised of.
Even the smallest micro behaviors or changes, right down to the atomic level, can be detected with a robust and usable signal. Extreme sensing such as needed for DNA sequencing or the binding activity of blending molecules for new drug discovery is now enabled, sending clear and actionable signals each time a new molecule is added to an existing one.
Graphene sensors are even known to measure the contractile strength of individual heart cells called ‘cardio myocytes’. When stimulated, these individual heart cells ‘beat’ like human heart. Previously, the only way to measure the pulse of these cells was to optically observe them and count the frequency of their contractions. Now, cardio-toxicologists can measure the strength of the ‘beat’ of each cell while simultaneously observing it optically, generating an entirely new measurement parameter for that field.
Versatility of Graphene Sensors for New Industries
Another useful application for graphene sensors in the field of life science is currently in the design phase. This includes the continuous detection and monitoring of blood pressure by wearing a watch or wrist band while it transmits systole, diastole, and pulse, real-time to a central database capture program at the doctor’s office using an application via the patient’s smartphone or other device. Thus, with minimal disruption using a virtually connected ‘Fitbit’-type device, one can monitor and send continuous blood pressure readings autonomously.
Outside of medicine, many other applications for graphene sensors are also under advanced development. One such example is the development of a micro-strain measuring graphene sensor that is capable of picking up incredibly minute deflection that can be layered into the wings or fuselage of airplanes to pick up in flight micro stress real-time. Immediately relaying that information to the pilot allows for efficient decision-making purposes far in advance of any catastrophic failure.
Additionally, these same types of graphene sensors can be inlaid into highway bridges or other infrastructure for predictive maintenance in a very cost effective way, now that the cost structures for these sensors has reached the ‘pennies per sensor’ regime. This means the associated applications are near limitless with this type of sensing.
“The increasing demand for highly sensitive, selective, cost-effective, low power consuming, stable and portable sensors has stimulated extensive research on new sensing materials. One of the most important features of a material to be used for sensing is its high surface-to-volume ratio. Nanostructures possess high surface-to-volume ratio which provides large active surface area for the interactions of molecules.” Two-dimensional materials for sensing graphene and beyond, Varghese et al., Electronics Magazine, August 3, 2015
With the availability, performance, durability, and flexibility of design possibilities for the implementation of pure carbon in the form of sheet graphene, the world of sensing is about to undergo a revolution. Major companies are now in advanced testing of the performance of monolayer graphene sensors with their product designs following close behind.
Graphene Sensors: The Tipping Point
Those leading in cutting-edge industries are starting to use graphene sensors as ‘key enablers’ not just incremental advancements to pre-existing designs. With practicality, performance, and ease of implementation now at hand, graphene sensors are ushering in entirely new fields of sensing that many didn’t realize were possible. Grolltex (‘graphene-rolling-technologies’) is one of the leading 2D materials companies in this field.
Grolltex has been supplying graphene sensor makers with base 2D sensing material for years. The company also manufactures these graphene sensor devices in their factory as a foundry service for customers. Furthermore, the company also designs and produces a line of patented graphene sensors for direct sales. One of Grolltex’s high demand services is taking its customers' ‘MEMS-fab made silicon-based’ designs and converting these silicon chip graphene sensors for manufacturing onto large sheets of plastic instead, at a cost-saving of over 100x the customer's current silicon fab and packaging schema.
While performance advantages of graphene sensors have been theoretically known by many in the sensing world for years, these advanced 2D devices have become real and can now be designed and created quickly, at a cost of pennies each. It is not too long before highly sensitive and robust graphene sensors start showing up in products across industry.
This information has been sourced, reviewed and adapted from materials provided by Grolltex Inc.
For more information on this source, please visit Grolltex Inc.