Invited Talk Title: Pneumatic Computers for Embedded Control of Physical Systems
Abstract: Alternative computing approaches that readily interface with physical systems (e.g., micro/millifluidics or soft robotics) are required to provide embedded control of such systems. We demonstrate both hard-wired and programmable finite state machines (i.e., simple computers) created as pneumatic circuits via normally closed microfluidic valves and channels. The finite state machine (FSM) is a widely employed abstraction in digital control systems and can be implemented efficiently with a limited number of logic gates. An FSM encodes the states and proper transitions between them. We demonstrate two pneumatic microfluidic FSMs with and without user inputs. We employ such FSMs to establish stand-alone microfluidics with embedded controllers. Specifically, we demonstrate a stand-alone rotary mixer (controlled via a two-bit FSM) and serial dilution (controlled via a four-bit FSM) microfluidic platform. These monolithic integrated systems require only pneumatic power to be supplied externally, in the form of a vacuum source. Additionally, user input can be provided directly to the chip by covering pneumatic ports with a finger. Finally, we demonstrate programmable FSMs. To this aim, we first create a programmable logic array (PLA) that a user can reconfigure by changing the hole-punch pattern on a membrane in the chip. We integrate the PLA with memory to create a two-bit programmable FSM. These pneumatic computers demonstrate a new framework for the embedded control of physical systems.
Bio: Siavash Ahrar is an assistant professor of Biomedical Engineering at the California State University of Long Beach. Siavash received his Ph.D. from the University of California Irvine under the mentorship of Prof. Elliot Hui. After his Ph.D., Siavash served as the first Science and Engineering Education Fellow (SEEF) with the Stanford University Department of Bioengineering from 2017-20. His work as a SEEF focused on realizing an active, effective, and inclusive curriculum for the bioengineering discipline. Currently, Siavash’s research group is focused on developing tools (including mili and microfluidics) and autonomous machines to study and engineer biological systems. Siavash also seeks to continue his efforts in studying and developing an active and accessible STEM education for all learners.
