Abstract: A power converter converts a digital input signal into an RF output power signal. A digital signal processor converts the input signal into one or more copies of a multi-bit RF signal. Each copy of the multi-bit RF signal is applied to a corresponding multi-bit current generator having a set of weighted, switched current sources, each of which is controlled by a different bit of the multi-bit RF signal. The currents from the different current sources are processed and combined to generate the output power signal.

Abstract: Fluid transfer devices described herein can include a body portion and a tip portion. A fluid pathway extends through the body and tip portions through which fluid may be transferred, for example, from a fluid-dispensing apparatus to a fluidic chamber of a microreactor. In some embodiments, the fluid transfer device is connected to the fluid-dispensing apparatus with an engaging element. The engaging element may be part of the body, and can enable the dispensing apparatus to repeatedly engage the body at one predetermined position. The body is capable of storing the fluid received from the dispensing apparatus. The tip portion may be formed of a rigid material (e.g., a metal), and/or may be configured to repeatedly pierce a septum without damaging either the tip or the body. Advantageously, in certain embodiments, the fluid transfer device can controllably transfer small volumes of fluid (e.g., 1 ?L) with a high degree of accuracy.

Abstract: An apparatus for performing a biological or biochemical reaction that, in certain embodiments, has the ability to apply shear stress to a component of a liquid sample and includes a biological or biochemical reactor comprising a container having a volume of less than about 2 mL and containing a liquid sample, and a shear-generating element, the shear-generating element being contained within the apparatus and constructed and arranged so that the entire shear-generating element moves along a selected path of motion intersecting a first location within the apparatus and a second location within the apparatus, with or without rotational movement is described. A method of applying shear stress to a component of a liquid sample that includes moving a liquid or gaseous shear-generating element within an apparatus along a selected path of motion to create a reproducible and controllable level of shear stress at a selected location within the liquid sample is also disclosed.