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

触觉是一种主导性感觉，它让我们体验周围的世界。今天的大多数电子设备都集成了电容式触摸界面，这是从手机、平板电脑到电子设备的流行技术。然而，电容式触摸无法提供与人类触摸相关的丰富体验--更具体地说，是触摸“深度”或力的概念。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也更难(也更昂贵)地采用它们。这一新兴的可折叠外形为用户提供了多功能设备的好处，该设备具有大面积显示屏，还可以折叠以舒适地放入口袋或包中。在这些情况下，转向更薄和更灵活的材料会增加与电容式触摸相关的噪音水平，从而增加错误触摸的发生，通常需要昂贵的补偿解决方案。Peratech Holdco有限公司开发了使用基于电阻的技术的力传感解决方案，该技术允许检测位置和力输入。在这个项目中，该研究员将探索Peratech的传感技术在显示模块堆叠中的集成。直接将触摸界面添加到显示屏中，而不是在显示屏上方或下方添加触摸界面，可以帮助最小化显示屏厚度(对于可折叠显示屏至关重要)，并减少需要在最终设备中组装在一起的各个工艺和层的数量。为了实现这一目标，该研究员将领导Peratech的力传感QTC墨水技术的微型化形式的开发，以及允许其集成到显示结构中的墨水沉积过程。这不是一项简单的任务，因为各个传感元件必须适合像素组件之间的显示技术的“黑色矩阵”，需要将图案尺寸降至10-30微米。需要针对数字沉积过程进行优化的新材料，包括功能颗粒的微型化和优化油墨系统的流变性以匹配沉积过程。为了实现这一目标，该研究员将与印刷电子有限公司合作，后者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(单个传感元件精确到10-30微米)，提供与力输入成正比的可调电阻。阵列设计将得到优化，以提供所需的特性，这将得到同时开发的计算模拟的帮助，计算模拟可以根据设计特征预测阵列性能。将产生驱动传感器阵列的电子系统，以及将传感器电阻转换为可以提取触摸位置和触摸力的信号的信号处理算法。这将被用来演示传感器阵列的功能，作为可以为用户提供丰富的新体验的3D触摸界面。集成到显示模块中是该项目的最终目标。这涉及在显示技术(例如，OLED或OLCD)内存在的像素阵列之间散布传感元件，即，将传感器结构直接构建在像素之间的“黑色矩阵”上。为了帮助实现这一点，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。它改变了用户与显示器(例如手机屏幕)的交互方式，将平坦的2D表面转变为丰富的触觉体验，从而提供了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.