Driving change in touch-panel industries: Development of a novel force sensor to enable 3D input in the next generation of foldable electronic devices

触觉是一种主要的感觉，它让我们能够体验周围的世界。当今的大多数电子设备都包含电容式触摸界面，这是从移动的电话和平板电脑到电子电器的流行技术。然而，电容式触摸未能提供与人类触摸相关联的丰富体验，更具体地，触摸“深度”或力的概念。它们也更难（也更昂贵）用于三星、华为、摩托罗拉等电子设备制造商正在开发的新一代可折叠电子设备。这种新兴的可折叠形状因子为用户提供了具有大面积显示器的多功能设备的好处，该显示器还可以折叠以舒适地放入口袋或包中。在这些情况下，向更薄和柔性材料的转变增加了与电容性触摸相关联的噪声水平，从而增加了假触摸的发生并且通常需要昂贵的补偿解决方案。Peratech Holdco Ltd使用基于连续性的技术开发力传感解决方案，该技术允许检测位置和力输入。在这个项目中，研究员将探索Peratech的传感技术在显示模块的堆叠中的集成。将触摸界面直接添加到显示屏中，而不是在显示屏上方或下方，可以帮助最大限度地减少显示屏厚度（对于可折叠显示屏至关重要），并减少最终设备中需要组装在一起的单个工艺和层的数量。为了实现这一目标，该研究员将领导开发Peratech力传感QTC油墨技术的一种简化形式，以及一种油墨沉积工艺，使其能够集成在显示结构中。这不是简单的任务，因为各个感测元件必须配合在像素组件之间的显示技术的“黑矩阵”内，需要图案化到10- 30 μ m的尺寸。需要针对数字沉积工艺进行优化的新材料，包括功能颗粒的分散和优化油墨系统的流变性以匹配沉积工艺。为了实现这一目标，研究员将与印刷电子有限公司合作，该公司是制造电子系统的数字，喷墨和其他印刷方法的专家。新的墨水系统将用于开发力传感阵列（单个传感元件低至10- 30微米），该阵列提供与力输入成比例的可调电阻。阵列设计将进行优化，以提供所需的属性，这将有助于同时开发的计算模拟，可以预测阵列性能的基础上的设计功能。将生产驱动传感器阵列的电子系统，沿着信号处理算法，以将传感器电阻转换成可以提取触摸位置和触摸力的信号。这将被用来展示传感器阵列作为“3D”触摸界面的功能，它可以为用户提供丰富的新体验。集成到显示模块中是该项目的最终目标。这涉及将感测元件散布在显示技术（例如OLED或OLCD）内存在的像素阵列之间，即，将感测结构直接构建到像素之间的“黑矩阵”上。为了帮助实现这一目标，显示结构将由领先的有机电子开发商FlexEnable Ltd提供。这项技术的成功开发为Peratech和更广泛的触摸界面行业提供了巨大的潜力。它提供了用户如何与显示器（例如移动的手机屏幕）进行交互的一个步骤，将平面2D表面转变为丰富的触觉体验，从而提供更直观和适应性更强的触摸界面。

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.