A project between Swedish company Insplorion and innovation consultancy RISE Acreo has found potential to build low cost nanosensors in large volume production for applications like battery monitoring.
Their preliminary study, "Miniaturization of a nanosensor system for batteries," verifies that it is possible to build very cheap fiber optic sensor systems that meet the requirements of battery sensing applications as well as others, such as in-vivo diagnostics and process industries. The study was carried out based on Insplorion’s nanoplasmonic sensing (NPS) technology, which exploits a physical phenomenon called localized surface plasmon resonance (LSPR).
The purpose of the study was to investigate the possibility of designing a fiber optic sensor system based on NPS for large-scale production at low cost.
"The key conclusions from the project are that it has been confirmed and clarified that we can use volume components that enable a competitive manufacturing price and how it will scale in manufacturing with larger volumes," said Patrik Dahlqvist, Insplorion's CEO. "We can build cheap sensor systems for a first series of batteries for niche applications. However, some technical development and verification are necessary to build the sensor systems that can reach the broad market."
The LSPR technology is a coherent, collective spatial oscillation of the conduction electrons in a metallic nanoparticle, which can be directly excited by near-visible light. The resonance condition (i.e. the wavelength/color of light which can excite the LSPR) is defined by a combination of the electronic properties of the nanoparticles, their size, shape and temperature, and the dielectric environment in close proximity of the nanoparticles.
Nanoplasmonic sensing exploits metallic nanoparticles, usually silver or gold, as local sensing elements, which offer a combination of unique properties; including ultrahigh sensitivity, small sample amount/volume (due to nanoparticle dimensions of the sensor, typically in the 50 – 100 nm size range), and capability for fast, real-time (millisecond time resolution) remote readout.
Source: Insplorion.
In Insplorion’s patent-pending nanoplasmonic sensing (NPS) chip architecture, the sensing is realized through nanofabricated arrays of non-interacting, identical gold nanodisks on a transparent substrate. This gold nanodisk array (the sensor) is then covered with a thin (few tens of nm) film of a dielectric spacer layer (see figure) onto which a sample material (e.g. nanoparticles or a thin film) is deposited. The sensor nanoparticles are thereby embedded in the sensor surface and not physically interacting with the studied nanomaterial, except via the LSPR dipole field. The latter penetrates though the spacer layer and has considerable strength on and in proximity to its surface and can, therefore, sense dielectric changes there.
Research firm Future Market Insights says the global surface plasmon resonance market is expected to expand at a compound annual growth rate of 6.3 percent during the period 2017-2027 and reach nearly $1.3 billion in revenues in 2027. It cites increasing demand for high end, surface plasmon resonance from end users — such as hospitals, clinics, ambulatory surgical centres, nursing centers and reference laboratories — for better throughput and performance, which will generate opportunities for using the surface plasmon resonance technique over the long run and drive growth.
Imaging systems will be one of the largest market segments it says, especially with increasing adoption of label-free detection techniques over labelled detection techniques. The other segment also anticipated to register significant growth is biosensors.
A recent application highlighted research from Soochow University, China, which uses LSPR technology in smart windows, which can adapt properties in response to environmental conditions, without any manual intervention. It is based on the adaptive behavior of thermochromic materials, which change color in response to changes in temperature. The prototype smart window utilizes LSPR to convert photons from ambient sunlight to localized thermal energy. This triggers the thermochromic window to switch from transparent to opaque, blocking further incoming sunlight.