Ultrasonically enabled supportless 3D printing (Sonobeamer)

在这份提案中，我们概述了我们将如何开发一种能够在没有物理支撑结构的情况下通过超声支持所需打印的3D打印的系统。这将有助于创建以前不可能实现的复杂几何形状，同时，对于大多数印刷品来说，通过消除对填充的需要以及移除物理支撑件，它将提高速度并减少每张印刷品所需的能量和材料量。消除对物理支持的需要也可以将这种打印方法产生的固体废物减少到零塑料废物。为了实现这一目标，我们将开发一种新型超声换能器阵列SonoBeamer，然后将其集成到演示3D打印设置中。SonoBeamer阵列将由瓷砖(约50x50 mm)组成，每个瓷砖最多包括208x208个换能器元件。每一块瓷砖本身都将由换能器或直板的线条组成，然后这些线将被组装成2D瓷砖。我们将设计定制的专用集成电路(ASIC)芯片，这些芯片将被粘合到连接到每个STEST的柔性电路板上。AISC芯片将在幅度和相位上提供精确的电脉冲序列，允许对超声换能器相控阵进行优化控制，同时将所用功率和产生的热量降至最低。在开发SonoBeamer阵列之前，我们将使用现成的超声换能器的较小阵列(12个元素)来测试设计参数，并使用该阵列来确定Sonobamer的最佳几何形状、阵列大小和每个像素的大小。我们的目标是将SonoBeamer瓷砖应用于立体平版印刷(SLA)3D打印，因此第一个小阵列将用于演示将3D打印对象保持在树脂中的方法。一旦我们开发了SonoBeamer瓷砖，我们将创建两个测试系统，我们将使用它们来演示它们的能力，并了解它们的能力和限制，以便我们可以使用第二代SonoBeamer设备进一步开发它们。第一个测试系统将基于定制的光学系统，并将在打印机的树脂槽的四面上安装SonoBeamer瓷砖。这将允许对树脂槽中的压力分布进行最佳控制，从而在印刷时对结构进行精细控制。我们将使用该系统开发算法和软件来驱动Sonobamer瓷砖，以在由正在创建的印刷结构创建的复杂环境中实现我们想要的控制。使用这个系统，我们将演示在印刷品形成时对印刷品的定向控制，使我们能够超越传统添加剂制造中的逐层印刷。我们还将演示该系统提供的新颖控制，通过将一个自由移动的对象完全打印在另一个打印对象中，例如一组嵌套的中空球体。在我们的第二个测试系统中，我们将把一组SonoBeamer瓷砖集成到一台商用SLA打印机的树脂槽中。由于我们不能将SonoBeamer瓷砖放置在该水箱的四个侧面，这将产生功能减少，方向控制较少，但它将允许打印的超声波支持，从而减少对填充和物理支持的需求。这将为我们提供一条快速途径，以提高商业系统的速度，减少能源和浪费。我们将把其中一个原型系统安装到我们的工业合作伙伴Step3D的制造设施中，他们将在商业环境中为我们测试它，并向我们反馈他们及其客户对该系统的优势和劣势。

In this proposal we outline how we will develop a system capable of 3D printing without physical support structures by ultrasonically supporting the desired print whilst it is being printed. This will facilitate the creation of complex geometries that previously were not possible whilst at the same time, for the majority of prints, by removing the need for infill as well as removing physical supports, it will increase the speed and reduce the energy and amount of material needed for each print. Removing the need for physical support could also reduce the solid waste created by this printing method to as low as zero plastic waste. To achieve this, we will develop a novel ultrasound transducer array, the SonoBeamer, which we will then integrate into demonstration 3D printing setups. The SonoBeamer array will consist of tiles (circa 50x50mm) with each tile comprising up to 208x208 transducer elements. Each tile will itself consist of lines of transducers, or staves, which will then be assembled into the 2D tile. We will design custom Application Specific Integrated Circuit (ASIC) chips which will be bonded onto a flexible circuit board attached to each stave. The AISC chips will give precise electrical pulse trains, both in amplitude and phase allowing optimised control over the phased array of ultrasound transducers whilst minimising the power used and the heat generated. Before developing the SonoBeamer arrays we will test the design parameters by using a smaller array (12 elements) of available off the shelf ultrasound transducers and use this to establish the optimum geometry, size of array and size of each pixel, for the Sonobeamer. We are targeting applying the SonoBeamer tiles to stereolithography (SLA) 3D printing and so the first small array will be used to demonstrate the method of holding a 3D printed object in resin whist it is being printed. Once we have then developed the SonoBeamer tiles we will then create two test systems which we will use to demonstrate their capabilities and learn their abilities and limitations so that we can further develop them with a second generation of SonoBeamer devices. The first test system will be based on a bespoke optical system and will have SonoBeamer tiles on four sides of the printer's resin tank. This will allow optimal control over the pressure distributions in the resin tank providing fine control over the structure as it is being printed. We will use this system to develop algorithms and software to drive the Sonobeamer tiles to achieve the control we want in the complex environment created by the printed structures being created. Using this system, we will demonstrate orientational control over the print as it is formed allowing us to go beyond printing layer by layer as in traditional additive manufacture. We will also demonstrate the novel control the system offers by printing of one freely moving object completely within another printed object e.g. a set of nested hollow spheres. In our second test system we will integrate a set of SonoBeamer tiles into a commercial SLA printer's resin tank. As we will not be able to place SonoBeamer tiles around four sides of this tank this will produce a reduced functionality, with less orientational control, however it will allow the ultrasonic support of the print so that the need for infill and physical supports will be reduced. This will give us a quick pathway to increasing the speed and reducing the energy and waste of commercial systems. We will install one of these prototype systems into the manufacturing facility of our industrial partners Step3D who will test it for us in a commercial setting and feedback to us the advantages and disadvantages they, and their customers, find with the system.