Silicon MEMS vaporizing liquid microthruster with internal microheater

Abstract

This paper reports a silicon MEMS vaporizing liquid microthruster (VLM) with an internal p-diffused microheater. The device fabrication and testing have been briefly described. The VLM consisting of two micromachined, bonded silicon chips produces thrusts in the range of 5 µN to 120 µN with a heater power of 1 W to 2.4 W at a water flow rate of 1.6 µl s −1 using an exit nozzle of throat size 30 µm × 30 µm. A maximum thrust of 120 µN was produced with a heater power of 2 W at a water flow rate of 0.7 µl s −1 with exit nozzle of throat size 50 µm × 50 µm. The measurement has been carried out using a sensitive cantilever and a laser based lamp-and-scale arrangement. The internal microheater is expected to yield a higher efficiency compared with the external microheater.

Cross-axis sensitivity reduction of a silicon MEMS piezoresistive accelerometer

“…Air gap of 20 lm is required for 30 lm flexure thickness to obtain the damping ratio of around 0.8. Due to non availability of a standard wafer bonding facility in the authors' laboratory, a strong epoxy adhesive was used in a two step bonding process (Maurya et al 2005) to fix the fabricated sensor with top and bottom pyrex cover plates. During the bonding process, the chips were aligned properly under a high power optical microscope and then sealed with the epoxy at atmospheric pressure.…”

Seed Bubble Guided Heat Transfer in a Single Microchannel

“…As an efficient heat transfer mode, boiling heat transfer is widely used in information [1], space [2], and biotechnologies [3]. Even though boiling heat transfer has been studied for more than a century, it is still difficult to control due to its random, nonrepeatable, and nonlinear behaviors.…”

Review of boiling explosion due to homogeneous nucleation in theoretical and experimental approach

“…Although uncontrolled boiling explosion may pose a potential hazard, boiling explosion under a controlled manner finds many interesting and practical applications ranging from an ink jet printer (Asai, 1989) to microelectronic cooling devices and micro bubble actuators in MEMS devices (Gad-el-Hak, 2002). Its applications have been into a new field such as development of bubble-actuated micro-fluidic devices, such as drug delivery systems (Staples, et al, 2006), vapor bubble micro pumps (Laser and Santiago, 2004), micro injectors (Lee, et al, 1999), micro thrusters and thermal bubble perturbators (Maurya, et al, 2005). The boiling phenomena concerned with these thermal micro-machines and MEMS applications differ from ordinal nucleate boiling in many aspects.…”