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The development and application of miniaturized hyperspectral imaging and sensing hardware has seen a commandable growth in the recent times. Of these, probably the stand-out development came from the VTT Technical Research Centre of Finland, whose team last year claimed that they had created the world's first hyperspectral mobile device by converting an iPhone camera into a new kind of optical sensor. Over recent years, the group has developed various types of novel hyperspectral imagers for applications ranging from skin-cancer detection to drone-based environmental monitoring and light-weight imagers for CubeSat space applications - all based around Fabry-Pérot interferometer tunable optical filters (FPIs).
According to the VTT research team leader Anna Rissanen, staff at VTT have also recently developed a new breed of MEMS-based FPIs that can be produced at high volumes and low cost - making them suitably cheap for use in smart phones. Based on their past work with more conventional hyperspectral imaging hardware, the VTT team now believes that the new technology could be suitable for a variety of different applications depending on the wavelength range - but has already singled out food quality sensing and health monitoring as the likely key sectors.
Although confidentiality agreements state that the team is not currently able to share detailed information about the ongoing commercialization of the MEMS-based hyperspectral imagers, they do reveal that VTT is aiming to engage with different types of companies, supply chains and end-user needs to find different potential paths for commercialization. The Technical Research Centre has certainly made solid progress in establishing partnerships with a wide range of established companies and startups in recent years - including Senop Oy (formerly Rikola), which worked with VTT to commercialize hyperspectral imagers for drone applications, and Revenio, which is currently commercializing a hyperspectral camera for skin cancer diagnostics.
Another initiative focusing on smart phone-integrated hyperspectral imaging for the food monitoring and safety is the new HawkSpex app under development at Fraunhofer IFF in Germany, which can be used to scan apples for pesticide residues. An initial laboratory-based version of the app has already been successfully trialled at IFF - with a commercial launch currently slated for late 2017.
One Israeli start-up, Unispectral - established in March 2016, is also working on a novel hyperspectral digital camera. The company believes that the new technology could be used for a number of applications in the burgeoning field of computer and machine vision as well as, can be built into smartphones. While most modern cameras today mimic the human eye, which registers light between 400 and 670 nm, by splitting light into red, green and blue pixels arranged as a Bayer Pattern, a typical CMOS image sensor is sensitive into the near-infrared, up to around 1000 nm. Increased flexibility in the wavelengths captured within and beyond the visible spectrum holds out the potential to enhance human-visible images in low-light and other situations. This flexibility, achieved by building a tunable wavelength optical filter as a MEMS device implementing a Fabry-Perot interferometer, means that the Unispectral team can displace two parallel optical surfaces to precisely select the frequency of transmitted light.
The filter design and the optical surface coatings set the filter transmission curves. The filter is integrated into the camera lens structure and displaces - or is added to - the Bayer RBG filter pattern. A driver and a set of algorithms manage the camera and the filter according to the particular application requirements, and when combining this solution with a conventional CMOS image sensors, delivers hyperspectral imagery across 400-1000 nm. A combination with different image sensors would yield a different wavelength range. The development appears to be catching some attention with the company recieving $7.5 million in Series A funding round, led by Jerusalem Venture Partners (JVP), Robert Bosch Venture Capital, the Samsung Catalyst Fund and the Tel Aviv University Technology Innovation Momentum Fund.
Unispectral has already identified several potential commercial applications and expects sectors like pharmaceuticals, precision agriculture, and food intelligence to benefit from what they describe as the 'democratization' of hyperspectral sensing. They currently are targeting multiple hosting platforms and aim to deploy the solution starting at 2018 and expand thereafter.
