Driving change in touch-panel industries: Development of a novel force sensor to enable 3D input in the next generation of foldable electronic devices
Lead Research Organisation:
Peratech Holdco Limited
Department Name: Research and development
Abstract
Touch is a dominant sense that allows us to experience the world around us. Most of today's electronic devices incorporate a capacitive touch interface, which is the prevalent technology from mobile phones and tablets to electronic appliances. However, capacitive touch fails to provide the rich experience associated with human touch - more specifically, the notion of touch "depth" or force. They are also harder (and more costly) to adopt on a new generation of foldable electronic devices under development by electronic device manufacturers such Samsung, Huawei, Motorola and others. This emerging, foldable, form factor offers users the benefit of a multi-function device with a large area display that can also fold to fit comfortably in one's pocket or bag. In these cases, the shift to thinner and flexible materials increases the noise levels associated with capacitive touch, thus increasing false-touch occurrences and typically requiring costly compensating solutions.
Peratech Holdco Ltd develop force-sensing solutions using a resistive-based technology, which allows both location and force input to be detected. In this project, the Fellow will explore the integration of Peratech's sensing technology within the stack-up of a display module. Adding the touch interface directly into the display instead of above or below it can help to minimise display thickness (vital for foldable displays) and reduces the number of individual processes and layers that need to be assembled together in the final device.
To achieve this, the Fellow will lead the development of a miniaturised form of Peratech's force sensing QTC ink technology, and an ink deposition process which allows it to be integrated within a display structure. This is no simple task, as the individual sensing elements must fit within the 'black matrix' of the display technology between the pixel assemblies, requiring patterning down to 10-30um size. New materials are needed which are optimised for a digital deposition process, including miniaturisation of the functional particles and optimising the rheology of the ink system to match the deposition process. To achieve this, the Fellow will collaborate with Printed Electronics Ltd, who are experts in digital, inkjet and other printing methods for manufacturing electronics systems.
The new ink system will be used to develop force-sensing arrays (with individual sensing elements down to 10-30um) which provide a tunable resistance proportional to the force input. The array design will be optimized to give the required properties, and this will be aided by the concurrent development of computational simulations which can predict array performance based on the design features. Electronic systems to drive the sensel array will be produced, along with signal processing algorithms to convert sensel resistance into a signal from which touch location and touch force can be extracted. This will be used to demonstrate the functionality of the sensel array as a '3D' touch interface which can provide a wealth of new experiences to the user.
Integration into a display module is the ultimate goal of the project. This involves interspersing the sensing elements between the pixel arrays present within a display technology (for example OLED or OLCD), i.e. building the sensel structures directly onto the 'black matrix' between pixels. To aid with this, display structures will be provided by FlexEnable Ltd, a leading organic-based electronics developer.
Successful development of this technology offers significant potential to both Peratech and the wider touch interface industry. It offers a step-change in how users can interact with their displays (for example mobile phone screens), turning a flat 2D surface into a rich, tactile experience which offers a more intuitive and adaptable touch interface.
Peratech Holdco Ltd develop force-sensing solutions using a resistive-based technology, which allows both location and force input to be detected. In this project, the Fellow will explore the integration of Peratech's sensing technology within the stack-up of a display module. Adding the touch interface directly into the display instead of above or below it can help to minimise display thickness (vital for foldable displays) and reduces the number of individual processes and layers that need to be assembled together in the final device.
To achieve this, the Fellow will lead the development of a miniaturised form of Peratech's force sensing QTC ink technology, and an ink deposition process which allows it to be integrated within a display structure. This is no simple task, as the individual sensing elements must fit within the 'black matrix' of the display technology between the pixel assemblies, requiring patterning down to 10-30um size. New materials are needed which are optimised for a digital deposition process, including miniaturisation of the functional particles and optimising the rheology of the ink system to match the deposition process. To achieve this, the Fellow will collaborate with Printed Electronics Ltd, who are experts in digital, inkjet and other printing methods for manufacturing electronics systems.
The new ink system will be used to develop force-sensing arrays (with individual sensing elements down to 10-30um) which provide a tunable resistance proportional to the force input. The array design will be optimized to give the required properties, and this will be aided by the concurrent development of computational simulations which can predict array performance based on the design features. Electronic systems to drive the sensel array will be produced, along with signal processing algorithms to convert sensel resistance into a signal from which touch location and touch force can be extracted. This will be used to demonstrate the functionality of the sensel array as a '3D' touch interface which can provide a wealth of new experiences to the user.
Integration into a display module is the ultimate goal of the project. This involves interspersing the sensing elements between the pixel arrays present within a display technology (for example OLED or OLCD), i.e. building the sensel structures directly onto the 'black matrix' between pixels. To aid with this, display structures will be provided by FlexEnable Ltd, a leading organic-based electronics developer.
Successful development of this technology offers significant potential to both Peratech and the wider touch interface industry. It offers a step-change in how users can interact with their displays (for example mobile phone screens), turning a flat 2D surface into a rich, tactile experience which offers a more intuitive and adaptable touch interface.
People |
ORCID iD |
| Description | Through this award, the team at Peratech have been able to demonstrate a force-sensing array which, when integrated under a display, can successfully detect both touch location and force to a touch accuracy within the specifications set by a key industrial display partner. The technology developed through the FLF can also be used to capture analogue input, e.g. handwriting from a stylus, including information on the touch force - which can be used to set the stroke width to give a natural digital handwriting experience. Meeting this key requirement allows the Fellow/team to begin to engage with industrial partners to drive the next stages of the project, and ultimately gets us one step closer to an intuitive, force-enabled solution which can disrupt existing touch technologies. |
| Exploitation Route | Any captured IP on the materials, processes and algorithms may be licensed by other industries. Ultimately, the end user of this technology would be anyone who owned a smartphone, tablet or other such device which contained Peratech's technology. |
| Sectors | Education,Electronics,Manufacturing, including Industrial Biotechology |
| Title | AI Based Time-Independent Tracking Method |
| Description | The model comprises a broad range of training data gathered on real sensors fabricated as part of the project, and a series of AI algorithms which leverage this model to apply to new datasets. |
| Type Of Material | Computer model/algorithm |
| Year Produced | 2022 |
| Provided To Others? | No |
| Impact | The training model and algorithms use add to the internal know-how of Peratech, a form of intellectual property, that adds value to Peratech. |
| Description | Printed Electronics Ltd - Inkjet and Digital Deposition |
| Organisation | Printed Electronics Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | The fellow and research team contribute to the design of force sensing elements which can be printed using either screen print techniques or digital deposition techniques including inkjet.The designs are created to complement the deposition process, and work with the requirements/constraints of the process. |
| Collaborator Contribution | Printed Electronics Ltd (PEL) provide ink formulation knowledge and expertise in both screen printing and digital deposition processes. For formulation work, PEL are able to advise and source off-the-shelf inks which can meet Peratech's requirements for the expected sensor functional behaviour. Where necessary, PEL also provide ink formulation services to create a bespoke ink formulation to meet the needs. PEL also provide access and training to print equipment, including several high-spec inkjet printers, to members of the Fellowship team. |
| Impact | Production of a force-sensing OLED touch panel demonstrator, which converts input in the form of a finger or stylus press onto the OLED surface, into a location and force coordinate. |
| Start Year | 2021 |
| Title | Force Sensing Device |
| Description | A force sensing device comprises a sensing array comprising a plurality of conductive rows and a plurality of conductive columns. The plurality of conductive columns are arranged to define a plurality of intersections. An electro-active layer comprised a pressure sensitive element at each intersection. A force concentrating structure is positioned at each intersection. |
| IP Reference | WO2022/034276 A1 |
| Protection | Patent / Patent application |
| Year Protection Granted | 2022 |
| Licensed | No |
| Impact | The patent gives us protectability for sensor designs which aid in the performance for force detection of very light forces. This is a key aim of the project. Furthermore, relevant IP adds to Peratech's patent portfolio and increases the company value. |
| Description | Attendence and Demonstration at SID Display Week, May 2023 |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | The Fellow and members of the Senior Management Team at Peratech attended SID Display Week in May 2022. The intended purpose was to meet with select customers (from large Display companies based in Asia) and show a physical demonstrator unit which showcased our stylus digitizer performance. The demonstrator was also shown to other companies / potential collaborators to highlight the future direction of Peratech's product roadmap. The impact included receiving positive feedback from a key technical director of China's largest display company (who the demonstrator was made in collaboration with) which has lead to a positive outcome for the project and significant interest in continuing to work together to integrate our technologies. The fellow (and wider group) could also see first-hand the trends and market changes in the industry associated with the fellowship - and this information was used to tune our internal development roadmap and research directions. |
| Year(s) Of Engagement Activity | 2022 |
| URL | https://www.displayweek.org/2022/Program/Program-Detail |
| Description | Presentation at FLEX Conference, July 2022 |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | The Fellow gave a talk at the FLEX conference, San Jose, which detailed major findings and achievements of the technology developed as part of the award. The talk was toward the target audience of the wider flexible electronics community, including potential partners, collaborators and customers. The talk lead to further conversations and discussions with interested parties who might wish to use this technology within their product. |
| Year(s) Of Engagement Activity | 2022 |
| URL | https://flex.semi.org/ |
| Description | Presentation at LOPEC March 2022 |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | We presented our under-display force-sensing solution at the LOPEC Conference in March 2022. The talk was titled 'An Ultra-Thin, Flexible & Bendable High-Resolution Force Sensing Array for Novel UI and Smart Surfaces', and was presented as part of the Technical Track during the conference. The presentation was also made available on the online platform for course attendees to download, and remote attendees to view. The purpose was to inform potential customers, collaborators and materials suppliers with Peratech's strategy for creating an under-display force sensing array, and detail the progress we have achieved to date. This was to create interest and buy-in to our company - so we can attract collaborators and materials suppliers, and promote our solution to intended customers in the printed electronics / display markets. An additional purpose is to engage with new partners to discuss opportunities for co-development. The impact included: > Introductions to new companies who's materials/processes could be incorporated into our technology - with follow up with at least 2 such companies. > Engagement with an electronic-ink (e-ink) display manufacturer, with the intention to collaborate in future - which lead to further meetings and the signing of an NDA to discuss project-specific activity. T |
| Year(s) Of Engagement Activity | 2022 |
| URL | https://lopec.com/application/en/program/schedule/lecture/an-ultra-thin-flexible-bendable-high-resol... |