A high performance MEMS platform for actuation and sensing

我们最近在我们的研究小组中开发了一种超薄（0.5毫米）新颖的3自由度微静电致动器平台，并通过初步实施的例子展示了它作为一个平台的潜力，可以解决微静电致动器长期存在的问题，以及它作为高性能微加速度计和力微传感器的用途。制造并测试了微致动器平台，以演示大的力产生和操作，最大质量为100毫克，行程为100微米。该技术需要进一步发展，以实现自动对焦（AF）和光学图像稳定（OIS）在智能手机相机。待开发的相机模块使用新型致动器来实现基于沿光轴平移和沿与图像传感器光轴垂直的轴形成平面的2轴旋转的自动对焦。使用图像传感器驱动实现自动对焦提供了几乎即时对焦，相机在很短的时间内将焦点从一个场景切换到另一个场景。另一个优点是执行器的高分辨率（±1µm），而不是目前广泛使用的电磁音圈电机技术（VCM）的±10µm分辨率。这种高分辨率使得使用大光圈相机可以让更多的光线进入图像传感器。OIS特性将通过使用第二个微致动器作用于镜头筒来实现。***该相机广泛用于手机，使用时观察到大量电池消耗。与目前使用的电磁vcm相比，该微致动器平台有望通过使用静电致动技术大幅降低功耗。我们的执行器的峰值功率要求为1兆瓦，而不是典型的vcm的100-200兆瓦。该技术在智能手机等手持设备中的实施要求MEMS执行器的工作电压限制在37V。该技术需要进一步发展，以使图像传感器信号在微芯片内路由，并将所需电压从80V降低到37V。通过实现相机的图像传感器和镜头筒的3个自由度运动，还需要进一步的开发来同时实现自动对焦和光学图像稳定。该微静电平台还将作为基于单一透明层的超灵敏力和位置传感器，用于开发智能手机的3D触摸屏。它也可以作为多轴加速度计来实现，其特点是大范围、宽带宽、超低本底噪声和由于设计本身而具有非常高的灵敏度，并且被证明非常适合需要非常高灵敏度的许多应用。

We have recently developed in our research group an ultra-thin (0.5 mm) novel 3-degrees-of-freedom micro-electrostatic actuator platform and shown through initial implementation examples its potential as a platform that can address long standing problems of micro electrostatic actuators as well as its use as a high performance micro accelerometer and force micro sensor. The micro actuator platform was fabricated and tested to demonstrate large force generation and manipulation of up to 100 milligram size masses and a stroke of 100 µm. Further development of the technology is needed for its implementation for autofocus (AF) and optical image stabilization (OIS) in smart phone cameras. The camera modules to be developed use the novel actuator to achieve AF based on translation along the optical axis and 2 axis rotation along axes forming the plane perpendicular to the optical axis of the image sensor. Achieving AF using image sensor actuation provides almost instant focus in which the camera switches the focus form one scene to another in a very short time. Another advantage is the high resolution (±1µm) of the actuator as opposed to ±10 µm resolution of the currently widely used electromagnetic Voice Coil motor technology (VCM). This high resolution enables the use of large aperture cameras which allow more light to enter the image sensor. The OIS feature will be pursued by acting on the lens barrel by using a second micro actuator. ***The camera is widely used in mobile phones and a significant battery drain is observed when used. The micro-actuator platform is expected to significantly reduce the power consumption by using electrostatic actuation technology as opposed to electromagnetic VCMs currently in use. The peak power requirement for our actuator is of the order of 1 mWatt as opposed to 100-200 mWatt for typical VCMs. The implementation of the technology in handheld devices such as smart phones requires that the operating voltages for the MEMS actuators are limited to 37V. Further development of the technology is needed to enable image sensor signal routing within the micro-chip and lower the required voltage from 80V to a maximum of 37V. Further development is also needed to achieve simultaneously autofocus and optical image stabilization by enabling 3 degrees of freedom motion of each the image sensor and lens barrel of the camera. The micro-electrostatic platform will also be implemented to develop 3D touch screens in smart phones by using it as an ultra sensitive force and position sensor based on a single transparent layer. It is also to be implemented as multi-axis accelerometers that are characterized by large range, wide bandwidth, ultra low noise floor and very high sensitivity due to the design itself and is shown to be uniquely suitable for a number of applications requiring very high sensitivity.