Dorian Liepmann (Advisor)

Research Advised by Professor Dorian Liepmann

Control of Fluids in Microscale Devices

Michael James DeBar
Dorian Liepmann
Albert P. Pisano
Richard M. White
2001
Pumping in microdevices due to gradients in surface tension was investigated both theoretically and experimentally. When a gradient in surface tension exists along an interface between two fluids, there is a net motion of the interface. The...

MEMS Based Micro-Capillary Pumped Loop for Chip-Level Temperature Control

Jeffrey Alan Kirshberg
Dorian Liepmann
Ralph Greif
Luke P. Lee
Kirk Yerkes
2000

Utilizing current Micro Electro Mechanical Systems (MEMS) technologies, a three-port micro-capillary pumped loop (micro-CPL) was designed, fabricated and tested to provide integral cooling to electronics or MEMS type devices. The two wafer design consists of...

Liquid to Vapor Phase Change in Constant Cross-Section Silicon Microchannels

Brenda Haendler
Albert P. Pisano
Dorian Liepmann
Kristofer S.J. Pister
2003
This paper presents research on the evaporation of methanol/water mixtures in uniformly heated, constant cross-section, serpentine silicon microchannels for potential application as a fuel injection system for a MEMS rotary engine. The phase change of a variety of mixtures of methanol and water was observed, characterized and compared to the phase change both of pure water and pure methanol. Seven different fluids were tested: pure water, pure methanol and five different molar fractions of methanol mixed with water....

An Integrated MEMS Syringe for Advanced Drug Delivery: Design, Fabrication and Fluid Mechanics of Suspension Flow through Microneedle Arrays

Boris Stoeber
Dorian Liepmann
Albert P. Pisano
Luke P. Lee
2002

New approaches for drug delivery seek to enable improved patient comfort as well as to provide an improved level of care. New approaches are especially important for drugs that cannot be administered orally. Liquid and lyophilized drugs can be delivered under the stratum corneum because of rapid diffusion of the drug into the capillary bed under the skin.

For this purpose, a syringe has been developed and fabricated using microfabrication to make an array of hollow, out-of-plane silicon needles using a combination of DRIE and isotropic etching. The needles have a typical height of...

Miniature-Scale and Micro-Scale Rotary Internal Combustion Engines for Portable Power Systems

Kelvin Fu
A. Carlos Fernandez-Pello
Albert P. Pisano
Kristofer J. Pister
Dorian Liepmann
2001

This work describes the development of both miniature-scale and micro-scale rotary internal combustion engines. This work is part of a project to develop a portable, high specific energy, liquid hydrocarbon-fueled power supply. A Wankel-type rotary engine was chosen for development because of its self-valving operation, planar geometry, and the ability to extract either mechanical or electrical power. To investigate engine behavior and design issues, larger-scale "mini-rotary'' engines have been fabricated from 4 steel. Mini-rotary engine chambers are approximately 1000 mm3 to 1 700 mm3 in...

Continuous Microfluidic Mixing Using Pulsatile Micropumps

Ajay Anil Deshmukh
Dorian Liepmann
Albert P. Pisano
Luke P. Lee
2001
Recent years have seen an explosion of interest in the field of microfluidics. Many possible applications exist for low cost, portable fluidic systems; examples include drug delivery devices, chemical reactors, and DNA sequencers. In many of these systems, the thorough mixing of small amounts of two or more fluids will be required. While it may at first seem that diffusion will be sufficient to quickly mix fluids in a sub-millimeter scale channel, this is often not the case. To meet this need, a new mixing process for...

Siebel Scholar Award 2019: Marc Chooljian

September 14, 2018
Congratulations to Siebel Scholar award recipient Marc Chooljian!

The Siebel Scholars program annually recognizes top students at the world’s leading graduate schools of bioengineering, business, computer science and energy science. The program, now in its 18th year, comes with a $35,000 award.

Read about it here: Eight Berkeley Engineers Honored as Siebel Scholars