Progressing development opportunities
Pursuing near-term opportunities in sensing
Nanoco has expanded its product and customer portfolio of nanomaterials for use in infrared sensing applications from a single customer and one material development programme in 2018 to five customers and eight different materials. Of these, the projects with ST and a very significant, undisclosed Asian chemical company are the most advanced.
Development with STMicroelectronics potentially leads to volume production in calendar 2023
Nanoco and ST have been working together for around three years. Originally this was as part of a supply chain for a major US customer, with Nanoco manufacturing nanomaterials that ST used to improve the sensitivity of its silicon infrared sensors. In June 2019 the US customer advised Nanoco that the joint programme would not be extended beyond December 2019 when the contract covering a range of stress tests and commissioning services at the Runcorn facility concluded. This decision was for reasons wholly unconnected to the performance of Nanoco’s materials and service delivery. The nanomaterials production facility in Runcorn had been successfully commissioned, with Nanoco delivering the final milestones for the US customer during FY20 and earning the contracted milestone payments in full.
With the US customer having withdrawn from the scene and the exclusivity agreement with it having lapsed, ST is able to offer the enhanced, proven, near infrared (NIR) sensors developed for the US customer across its extensive, global customer base. In May 2020 ST signed a framework agreement with Nanoco covering both development work and commercial supply of nanomaterials for use in multiple infrared sensing applications over a five-year period. The agreement covers the supply of small-scale volumes of nanomaterials for NIR sensors. It also covered a development project, which initially extended from April to December 2020, on a new generation of nanomaterials for potential use in other infrared sensing applications, which we infer from a recent paper given by ST (see below) are in the short-wave infrared (SWIR) range. This development activity was not impaired by the coronavirus pandemic. During H121 Nanoco successfully delivered all of the technical and commercial milestones on the first phase of this project, which contributed £0.8m of the total £1.0m revenues for the period. In May 2021 Nanoco announced that it was working on the second phase, which is the optimisation of the new materials. This phase is scheduled to complete in Q122. If successful, this phase could lead to production scale-up and eventual volume production in calendar 2023.
The agreement also commits ST to taking a specified minimum volume of nanomaterials from Nanoco if the enhanced sensors gain market traction and commercial volumes are required. These materials would be produced at the existing facility dedicated to sensing applications in Runcorn, which has already demonstrated that it can deliver material in commercial volumes and has the capacity to manufacture c £100m of materials each year. The volume production facility for sensor materials in Runcorn was closed temporarily during the first lockdown and has since been reopened.
Development agreement with Asian chemical company addresses different supply chains
In July 2021 Nanoco announced that it had signed a development agreement for a project with a very significant Asian chemical company. Nanoco had previously supplied this Asian customer with nanomaterial for infrared sensing applications and has recently completed feasibility work on a potential new nanomaterial operating at a different wavelength which will be suitable for use in electronic devices across a number of sensing applications and end-markets. The Asian customer intends to incorporate Nanoco’s nanomaterials in its own materials, which it will sell globally to companies making electronic devices (ie companies at a similar level in the supply chain to ST). The first phase of the development project with the Asian customer is scheduled to complete in calendar H221 (ie first half of FY22). If successful, there will be a further two development phases extending to the end of FY22 (July 2022). There would then need to be a scale-up phase, suggesting that any volume production for the customer would not commence until FY24 (ie one year to 18 months after any potential volume ramp-up for ST).
The value of this project is modest at present. The total value of work for the Asian customer during FY21, including the preliminary feasibility studies that have already taken place, is c £0.2m. Assuming that the first phase is successful and Nanoco proceeds with the two subsequent development phases, this could represent c £0.2m in revenue in FY22. However, Nanoco’s engagement with this Asian customer demonstrates that interest in the use of Nanoco’s quantum dots for infrared sensing applications continues to grow and that Nanoco is succeeding in expanding its customer base.
Using quantum dots for sensing applications
There is interest from ST, the significant Asian chemical company and others in using Nanoco’s HEATWAVE QD nanomaterials to extend the range of existing CMOS image sensors, which are made from silicon, out into the NIR and SWIR parts of the spectrum, that is the section from 900nm out to 1,800nm. This is because silicon sensors have adequate sensitivity in the visible part of the spectrum, but not in the infrared part. NIR sensors are used for facial recognition and AR applications in mobile phones, and for collision avoidance systems in autonomous vehicles. Silicon-based sensors are not as sensitive as sensors based on the compound semiconductor indium gallium arsenide (InGaAs) but are much less expensive to manufacture. Moreover, unlike the compound semiconductor option, a silicon sensor can readily be integrated with a silicon-based read-out circuit, further reducing cost. Depositing a layer of QDs tuned to the IR frequency of interest on the sensor potentially provides a cost-effective route for improving the range and sensitivity of sensors. Enhanced sensitivity results in lower power consumption, which for a mobile phone user means longer time between charges.
In May 2021, ST presented a paper at the Society for Information Display’s annual symposium. This announced that ST was ready to commercialise its QD photodetector platform technology and intended to have 940nm engineering samples ready for release to early adopters during calendar H221 and short-wave infrared (SWIR, <1,400nm) samples ready during calendar 2022. The paper noted that the technology held great promise for enabling lower cost (100–1,000 times lower), high-performance, high-resolution, large spectral response image sensors, which would potentially drive large SWIR imaging growth. It identified initial opportunities in mobile devices, miniature spectrometers and hyperspectral imaging, machine vision and advanced driver assistance, noting that the variant currently at R&D scale was likely to surpass the required performance specifications including sensor speed for time of flight applications (see below) in future. Belgian research institute IMEC and camera manufacturer SWIR Vision Systems also presented papers on the use of QDs in infrared imaging at the same event.
Biometric facial recognition: 940nm wavelength
Biometric facial recognition typically uses a structured light approach where a fixed pattern of light such as parallel stripes are projected onto the face and the camera analyses the distortion of the reflected image to construct a 3D reconstruction of the face. A safe, non-visible light wavelength is used so as not to be intrusive for the user. Typically 940nm is used because suitable emission sources are readily available. Common silicon image sensors have poor sensitivity at the required 940nm wavelength unless a costly process modifying the wavelength of all light incident on the sensor by a specific amount is used. Treating the sensors with HEATWAVE QDs improves their efficiency in the NIR region, reducing the amount of power required, and improves the speed at which facial recognition takes place. In addition, the sensors still work efficiently at visible wavelengths, so the same camera module can provide multiple functions in the same device, saving both space and cost.
Optical diagnostics: 400–1,650nm wavelength
Optical diagnostic systems are a way of monitoring a patient’s condition without having to take samples of blood. The systems send pulses of light through a patient’s skin and measure the amount of absorption and scattering that has occurred. The light can be tuned to a specific wavelength for detecting the levels of different molecules in the patient’s blood: 575nm for haemoglobin, which indicates the amount of oxygen in the blood; 455nm for bilirubin, which indicates liver function; and 1,650nm for glucose, which helps diabetics monitor the amount of insulin required. For a specific molecule at a specific wavelength, the level of absorption and scattering can be used to determine the levels of the target molecule in a patient’s blood, proving a non-invasive diagnostic path. Using a QD sensor improves efficiency compared with a silicon-based sensor, thus reducing power consumption, which extends usage time between charges for a user who is wearing the device all the time, for example for managing diabetes. The QDs also mean that sensors with small pixel size can be used. (ST cite pixel pitches of 2.2 µm and 1.6 µm.) This is beneficial for devices implanted in the hypodermis for analysis of interstitial fluid, where comfort for the patient also needs to be considered.
Range finding (LiDAR): 1,450nm and 1,550nm wavelengths
LiDAR works by measuring the amount of time it takes for an emitted beam of light to bounce off a target and be picked up by a detector and using that time to calculate the target distance. The round-trip takes less time for objects that are nearer. This is referred to as time of flight (ToF) detection. An array of emitters and detectors can be used to construct a 3D image of objects within the sensor’s field of view. LiDAR technology is being adopted in a range of fields including machine vision, autonomous vehicles, geographical mapping, incoming wind detection for wind turbines and military targeting. Significantly, the new iPhone 12 Pro includes a world-facing LiDAR scanner to improve AR experiences. The ability to integrate more accurate information about a handset user’s physical environment into the AR world could potentially catalyse the launch of ‘must-have’ AR apps. Emergence of such apps would not only be beneficial for iPhone 12 Pro sales but also encourage Android handset manufacturers to add LiDAR to their devices.
Sensors for range finding and LiDAR applications need to ensure that sunlight reflected from the general surroundings does not swamp the emitted or reflected light beams, so the wavelengths are chosen outside the visible part of the spectrum where the intensity of the sunlight will already have been reduced by natural effects such as water vapour. The 940nm wavelength used for facial recognition in mobile phones is not suitable because the longer distances involved require the use of more powerful beams of light, posing safety issues if people look into the beam of light. This potentially limits the use of LiDAR in autonomous vehicles, where higher power beams are required, holding back vehicle deployment. The power issue is being addressed by using longer wavelengths of light, which are eye-safe. Nanoco’s HEATWAVE QDs have demonstrated high efficiencies at these wavelengths. This helps improve LiDAR range without having to turn up the power and results in fast response times, which is useful for detecting rapidly moving objects.
Night vision: 700–1,100nm wavelength
Night vision applications typically use NIR light from the moon or an external illumination source to obtain images in low light situations. Current CMOS technology has relatively low pixel resolution at these wavelengths, forcing a choice between low final image resolution or over-sized sensor arrays. Nanoco’s HEATWAVE QDs enable high resolution CMOS sensors designed for visible light to operate efficiently at these longer wavelengths, enabling viewers to obtain highly detailed images for target identification.