The world’s leading experts, engineers, strategists and researchers can all be found at the Sensors Expo, San Jose, and we had the privilege to catch up with Dr. Benjamin Bunes, The Director of Research and Development at Vaporsens working on nanofiber-based chemical sensor technology.
For those not in the know, this small tech offers an accurate method of detection for vapor-phase chemicals, such as explosives, air pollutants, narcotics, etc.
Dr. Bunes will be offering an overview of the science behind this nanofiber-based chemical sensor technology, explaining the application for it including uses in outdoor air quality monitoring, personnel protection, and food spoilage sensing. Check it out here.
Do the sensors need to be „refreshed“ and do they wear out, or does the tech provide continues data as long as there is a power supply?
Dr. Benjamin Bunes: Vaporsens’ nanofiber sensor technology does not generally need to be refreshed in typical use cases in which the target chemicals are volatile or semi-volatile. Non-volatile substances, such as explosives, tend to remain on any surface they land upon, including nanofibers. In these cases, the sensors can be refreshed by a bake-out in a vacuum oven or exposure to the vapor of a solvent, such as acetone. Sensors are also field replaceable. Most chemicals we work with, such as formaldehyde, ammonia, triethylamine, hydrochloric acid, hydrofluoric acid, and chlorine, do not require any special refreshing process. They will refresh automatically when the sensor is no longer exposed to the chemical.
Sensors are typically operating in conjunction with a sampling system that provides a clean air reference. Data is reported in discrete intervals (for example, every 10 minutes). Continuous monitoring is a goal that we are working toward and expected to achieve in late 2019 or early 2020.
What other challenges did you overcome?
Dr. Benjamin Bunes: One challenge that we have faced is building instrumentation for the wide range of sensor materials we have developed. So far, we have created ~150 unique nanofiber materials, each with its own characteristics, including selectivity toward different chemicals, morphology, conductivity, and solubility. Conductivity, for example, results in sensor currents that range from low picoamperes to milliamperes. Producing electronics capable of reading picoampere level currents with low noise is a challenge – getting those same circuits to also read milliamperes is a major feat! We have done so by finding methods to boost our signal, both through photoexciting the nanofibers to increase their conductivity and by creating tunable amplification circuits to accommodate the wide range of currents from the various sensors.
Due to the size, do you see this technology integrating into cell phones, wearables, and clothing, providing a nearly unlimited reach of health, atmospheric and perhaps weather data?
Dr. Benjamin Bunes: Vaporsens’ sensors are small and consume little power. They are very suitable for integration into cell phones or wearables. In fact, Vaporsens is developing wearable sensors for the first responder community. In this case, we are actively searching for narcotics to provide an early warning of the potential for an incidental dose. We are also exploring a number of other areas that can benefit from our small size, lightweight, and low power requirements, in addition to our sensitivity and sensitivity. These other areas include mounting sensors on small unmanned systems. These implementations open the door for many applications in health, safety, and environmental monitoring.
How will OEMs need to adjust their processes to anticipate and accept nanofiber-based chemical sensor technology? Are there any processes hindering a potential rollout and what needs to change?
Dr. Benjamin Bunes: Vaporsens is focused primarily on providing end-to-end solutions for our customers. However, we do engage with OEMs to provide sensors to integrate into their systems. In these cases, we will work with the OEM to engineer our sensors to exact specifications. Such close collaboration ensures that the OEMs are aware of any adjustments that need to be made early in the development process; in most cases, we can adapt our technology to fit their needs instead of requiring adjustments to processes. Our approach to OEMs is to take each on a case-by-case basis rather than a one size fits all approach. More information can be found on our website.
Facilitating rollout to an OEM requires us to perfect and scale-up our manufacturing processes. As an early-stage company, we currently make sensors in small batches. We are working to grow our manufacturing capabilities and expect to increase our capabilities significantly over the next year. A number of studies are underway to build our manufacturing capabilities.