## GRAPH NAME LIQUID CHIPS *** *** ## NODE 1 **NAME** TESLA VALVE **DATE** 1920 **PLACE** USA **WHO** Nikola Tesla **BRIEF DESCRIPTION** Tesla patented a valvular conduit — a passive fluidic diode with no moving parts — that redirects fluid flow based purely on channel geometry. The device exhibits non-linear response and frequency-dependent diodicity. Although conceived as a mechanical device, it established the foundational principle that geometry can encode logical behavior in fluids, predating fluidic logic by nearly four decades.[1] **LINK** https://en.wikipedia.org/wiki/Fluidics *** ## NODE 2 **NAME** MONIAC **DATE** 1949-11-29 **PLACE** United Kingdom - England - London **WHO** Bill Phillips / London School of Economics **BRIEF DESCRIPTION** The Monetary National Income Analogue Computer (MONIAC), built by New Zealand economist Bill Phillips, is a hydraulic analogue computer that uses water moving through tanks, pipes, and valves to simulate national economic flows. It simultaneously solves nine differential equations. MONIAC is the first operational fluid-based computing system, demonstrating that analog computation is achievable entirely through fluid mechanics without electronic components.[2][3] **LINK** https://www.computinghistory.org.uk/det/43833/Professor-Bill-Phillips-unveils-MONIAC-at-the-LSE/ https://www.fieldsjournal.org.uk/article/444/galley/201/download/ *** ## NODE 3 **NAME** FLUID AMPLIFIER **DATE** 1957 **PLACE** USA - Maryland **WHO** Billy M. Horton / Harry Diamond Laboratories **BRIEF DESCRIPTION** Billy M. Horton of the Harry Diamond Laboratories proposed the first fluidic amplifier by recognizing that a small fluid stream can redirect a larger fluid jet — the wall-attachment (Coanda) effect applied to control. By 1959, Horton, R.E. Bowles, and Ray Warren constructed working vortex amplifiers from simple materials, launching the field of fluidics. This work directly enabled the first generation of digital and analog fluidic logic devices in the 1960s.[1][4] **LINK** https://en.wikipedia.org/wiki/Fluidics https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0168267 *** ## NODE 4 **NAME** FLODAC **DATE** 1964 **PLACE** USA **WHO** IBM / Fluidic Logic Group **BRIEF DESCRIPTION** The FLODAC (FLuid Digital Automatic Computer) was built in 1964 as a proof-of-concept digital computer based entirely on fluidic logic elements. It demonstrated that binary digital computation was achievable using fluid jet interactions without any electronic transistors. FLODAC remains the first documented all-fluidic digital computer, validating the theoretical capability of fluid-based Boolean logic at scale.[1] **LINK** https://en.wikipedia.org/wiki/Fluidics *** ## NODE 5 **NAME** FLUERIC DEVICES **DATE** 1965 **PLACE** USA **WHO** Harry Diamond Laboratories / US Army **BRIEF DESCRIPTION** Flueric devices are fluidic logic elements with no moving parts, relying entirely on fluid stream interaction and wall-attachment for logic operations. By the mid-1960s, AND, OR, NOT, XOR gates, counters, and shift registers had been demonstrated in fluid. These devices were deployed industrially in jet sensing, nuclear reactor coolant control, missile guidance, and artificial heart-pump systems — representing the first real-world use of liquid computing logic in critical applications.[1][4] **LINK** https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0168267 https://ntrs.nasa.gov/api/citations/19730002533/downloads/19730002533.pdf *** ## NODE 6 **NAME** Si GC CHIP **DATE** 1975 **PLACE** USA - California - Stanford **WHO** Stephen C. Terry / Stanford University **BRIEF DESCRIPTION** Terry fabricated the first microfluidic chip on a silicon wafer using photolithography and chemical etching — a miniature gas chromatography (GC) system with a 1.5-meter capillary column on a 5-cm wafer. The system reduced instrument size by nearly three orders of magnitude versus laboratory-scale systems. Published in IEEE Transactions on Electron Devices in 1979, this work established the foundation for silicon-based microfluidic fabrication, directly enabling the µTAS concept.[5][6][7] **LINK** https://www.semanticscholar.org/paper/A-gas-chromatographic-air-analyzer-fabricated-on-a-Terry-Jerman/a0b5b05ba6925f4f8c3cb6985d8d https://ntrs.nasa.gov/citations/19800036046 *** ## NODE 7 **NAME** µTAS CONCEPT **DATE** 1990 **PLACE** Switzerland **WHO** Andreas Manz / Ciba-Geigy / University of Basel **BRIEF DESCRIPTION** Andreas Manz, N. Graber, and H.M. Widmer published the seminal paper "Miniaturized Total Chemical Analysis Systems" in Sensors and Actuators B, defining the µTAS concept: integrating all steps of chemical analysis — sampling, separation, detection — onto a single microchip using IC microfabrication. This paper launched the modern field of lab-on-a-chip technology and defined the design philosophy for microfluidic chips as analytical instruments.[8][9][10] **LINK** https://www.semanticscholar.org/paper/Miniaturized-total-chemical-analysis-systems:-A-for-Manz-Graber/a1c1019cd3400ffeb2c92abc42 https://pubmed.ncbi.nlm.nih.gov/14714150/ *** ## NODE 8 **NAME** EWOD CONCEPT **DATE** 1993 **PLACE** France **WHO** Bruno Berge / Université Joseph Fourier **BRIEF DESCRIPTION** Bruno Berge defined electrowetting-on-dielectric (EWOD): the modulation of liquid contact angle on an insulating layer via applied voltage. EWOD enables programmable control of individual droplets (dispensing, merging, splitting, transport) using electrode arrays. This principle became the operational basis of Digital Microfluidics (DMF) and later enabled biochip platforms for PCR, immunoassays, and DNA analysis without mechanical pumps.[11][12][13] **LINK** https://en.wikipedia.org/wiki/Electrowetting https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/electrowetting *** ## NODE 9 **NAME** PDMS SOFT LITH **DATE** 1998 **PLACE** USA - Massachusetts - Cambridge **WHO** George Whitesides / Harvard University **BRIEF DESCRIPTION** Whitesides and colleagues published rapid prototyping of microfluidic devices using PDMS (polydimethylsiloxane) and soft lithography in Analytical Chemistry in 1998. This fabrication method — pouring liquid PDMS over a mold and curing — drastically reduced the cost and time for microfluidic chip manufacturing, opening the technology to non-experts across biology, chemistry, and engineering. It is the most cited enabling method in the microfluidics field.[8][9] **LINK** https://pubmed.ncbi.nlm.nih.gov/16871203/ https://www.inrf.uci.edu/cadmim/wp-content/uploads/2013/06/ALee_LOC_May2013.pdf *** ## NODE 10 **NAME** MULTILAYER SLITH **DATE** 2000 **PLACE** USA - California - Pasadena **WHO** Stephen Quake / California Institute of Technology **BRIEF DESCRIPTION** Quake and colleagues published multilayer soft lithography in Science (2000), enabling integrated pneumatic microvalves, pumps, and mixers on PDMS chips. This was the first demonstration of large-scale integration (hundreds of valves) in microfluidics. The technique allowed complex fluid routing, sequential control, and on-chip flow regulation — transforming microfluidic chips from passive channels to active, programmable systems.[8] **LINK** https://www.inrf.uci.edu/cadmim/wp-content/uploads/2013/06/ALee_LOC_May2013.pdf *** ## NODE 11 **NAME** OPTOFLUIDICS **DATE** 2006 **PLACE** USA - California - Pasadena **WHO** Demetri Psaltis / Changhuei Yang / Caltech **BRIEF DESCRIPTION** Psaltis, Yang, and Quake defined "optofluidics" in Nature (2006) as the integration of microfluidics and optics in a single chip platform. Liquid fills optical channels, enabling tunable lenses, waveguides, and light-based sensors where the optical properties are reconfigured by changing the liquid. Optofluidic chips achieve functions impossible in solid-state systems, including continuously tunable refractive index and reconfigurable optical paths.[14][15][16] **LINK** https://www.epfl.ch/labs/lo/wp-content/uploads/2018/08/Nature_442_381_Jul2006.pdf https://pmc.ncbi.nlm.nih.gov/articles/PMC2921414/ *** ## NODE 12 **NAME** BUBBLE LOGIC **DATE** 2007-02-09 **PLACE** USA - Massachusetts - Cambridge **WHO** Manu Prakash / Neil Gershenfeld / MIT **BRIEF DESCRIPTION** Prakash and Gershenfeld demonstrated universal digital computation in an all-fluidic two-phase microfluidic system in Science (2007). Air bubbles in liquid-filled microchannels act as bits; bubble-to-bubble hydrodynamic interactions produce nonlinearity. The authors demonstrated AND/OR/NOT gates, a toggle flip-flop, a ripple counter, timing restoration, a ring oscillator, and an electro-bubble modulator — all required properties for scalable universal computation. This is the first demonstration of Turing-complete computation in a purely fluidic medium.[17][18][19] **LINK** https://www.science.org/doi/10.1126/science.1136907 https://pubmed.ncbi.nlm.nih.gov/17289994/ https://prakashlab.stanford.edu/publications/microfludic-bubble-logic *** ## NODE 13 **NAME** LUNG ON A CHIP **DATE** 2010 **PLACE** USA - Massachusetts - Boston **WHO** Donald Ingber / Dan Huh / Wyss Institute Harvard **BRIEF DESCRIPTION** Ingber, Huh, and colleagues published the first living human lung-on-a-chip in Science (2010). A PDMS microfluidic device lined with two layers of living human cells (lung epithelium and endothelium) separated by a porous flexible membrane recreates the air-liquid interface and cyclic mechanical stretch of breathing. The device reproduces physiological and pathological lung responses, establishing organ-on-a-chip as a validated platform for disease modeling and drug testing.[20][21][22][23] **LINK** https://wyss.harvard.edu/technology/human-organs-on-chips/ https://cen.acs.org/biological-chemistry/tissue-engineering/Donald-Ingber-leading-efforts-develop/96/i26 *** ## NODE 14 **NAME** DMF BIOCHIP **DATE** 2010 **PLACE** USA **WHO** Advanced Liquid Logic / Duke University **BRIEF DESCRIPTION** Advanced Liquid Logic, founded by Richard Fair of Duke University, commercialized the first EWOD-based digital microfluidic biochip platform for clinical assays including immunoassays and genotyping. The platform uses a programmable electrode array to manipulate nanoliter droplets for DNA amplification, enzymatic reactions, and sample preparation. The system was later acquired by Illumina, validating DMF as a manufacturable technology for precision molecular diagnostics.[12][24] **LINK** https://en.wikipedia.org/wiki/Digital_microfluidics https://pubs.rsc.org/en/content/getauthorversionpdf/d0lc00144a *** ## NODE 15 **NAME** FLUIDIC LOGIC V2 **DATE** 2012 **PLACE** USA - California - Stanford **WHO** William Grover / Manu Prakash / Stanford University **BRIEF DESCRIPTION** Grover and colleagues published pressure-driven digital logic in PDMS multilayer soft lithography chips in Lab on a Chip (2012), demonstrating NOT, NAND, NOR gates, bistable flip-flops, oscillators, peristaltic pumps, delay elements, and a 12-bit shift register. This system showed cascadability, feedback, programmability, and autonomous control fully analogous to electronic logic. It resolved earlier timing issues of bubble logic by operating in continuous-phase laminar flow.[25] **LINK** https://pubs.rsc.org/en/content/articlelanding/2012/lc/c2lc21155f *** ## NODE 16 **NAME** PAPER MICROFLUIDICS **DATE** 2007 **PLACE** USA - Massachusetts - Cambridge **WHO** George Whitesides / Harvard University **BRIEF DESCRIPTION** Whitesides and colleagues introduced paper-based microfluidic analytical devices (microPADs) using wax patterning to define hydrophilic channels in nitrocellulose. The devices wick fluid passively by capillary force without external pumps. At cent-level fabrication cost, paper microfluidics enabled colorimetric point-of-care diagnostics for glucose, protein, and pH in resource-limited settings. Published in Angewandte Chemie, this work established paper as a legitimate microfluidic substrate.[8] **LINK** https://www.inrf.uci.edu/cadmim/wp-content/uploads/2013/06/ALee_LOC_May2013.pdf *** ## NODE 17 **NAME** 3D PRESSURE GATES **DATE** 2019 **PLACE** Saudi Arabia / USA **WHO** Muhammad Hussain / Nazek El-Atab / KAUST **BRIEF DESCRIPTION** El-Atab, Hussain, and colleagues demonstrated pressure-driven 3D microfluidic Boolean logic gates using multilevel PMMA polymer sheets with aligned microchannels in Advanced Science (2019). The presence or absence of fluid at gate outputs encodes binary 1 and 0. The system implements AND, OR, XOR gates and a half adder using any non-functionalized fluid — eliminating the need for specialized working liquids. The 3D architecture enabled cascading of gates toward large-scale microfluidic computing.[26][27] **LINK** https://pmc.ncbi.nlm.nih.gov/articles/PMC6974944/ https://pmc.ncbi.nlm.nih.gov/articles/PMC6974940/ *** ## NODE 18 **NAME** IONTRONIC MEMRSTOR **DATE** 2023-06-26 **PLACE** Netherlands - Utrecht **WHO** T.M. Kamsma / R. van Roij / Utrecht University **BRIEF DESCRIPTION** Kamsma, van Roij, and colleagues published the iontronic conical microfluidic memristor in Physical Review Letters (2023). A tapered microfluidic channel filled with aqueous electrolyte exhibits history-dependent conductance arising from transient concentration polarization over the ionic diffusion time — an intrinsic memory mechanism. The authors proposed and theoretically validated an equivalent of the Hodgkin-Huxley neuron circuit, showing all-or-none action potentials and spike trains. This established microfluidic memristors as viable neuromorphic computing elements.[28] **LINK** https://link.aps.org/doi/10.1103/PhysRevLett.130.268401 *** ## NODE 19 **NAME** WATER CHIP **DATE** 2024-01-21 **PLACE** China - Zhejiang - Hangzhou **WHO** Minhui Yang / Shisheng Lin / Zhejiang University **BRIEF DESCRIPTION** Yang, Lin, and colleagues introduced a water-based optoelectronic computing chip using graphene/water/semiconductor photodetector arrays (arXiv 2024). The device exploits the exponential decay of water molecule polarization transfer function (PTF) along the signal direction, enabling logic operations with energy consumption of approximately one attojoule (10⁻¹⁸ J) per operation. A single water molecule flip has a timescale of 25 femtoseconds. An 8×8 array chip demonstrated Multiply-Accumulate (MAC) computations for ASCII pattern recognition.[29] **LINK** https://arxiv.org/abs/2401.11514 *** ## NODE 20 **NAME** IONTRONIC LOGIC **DATE** 2024-05 **PLACE** Netherlands - Utrecht / South Korea **WHO** Tim Kamsma / Utrecht University / Leiden University **BRIEF DESCRIPTION** Kamsma and colleagues demonstrated the first aqueous memristor emulating biological short-term synaptic plasticity through ion transport in water, published in the Proceedings of the National Academy of Sciences (2024). The device uses only salt and water as information-carrying medium — the same carriers used by biological neurons. This is the first experimental demonstration of synaptic plasticity features in an all-aqueous iontronic device, representing a fundamental shift from solid-state neuromorphic hardware.[30] **LINK** https://thedebrief.org/new-iontronic-memristor-could-revolutionize-brain-like-computing-using-only-salt-and-water/ https://pmc.ncbi.nlm.nih.gov/articles/PMC6974940/ *** ## NODE 21 **NAME** IONTRONIC GATES **DATE** 2025 **PLACE** Netherlands - Utrecht **WHO** T.M. Kamsma / R. van Roij / Utrecht / Soft Matter RSC **BRIEF DESCRIPTION** Kamsma and colleagues published microfluidic memristive oscillators as universal logic gates in Soft Matter (RSC, 2025). The iontronic memristor oscillator implements XOR and NAND operations — functionally complete gate sets — using only electrolyte-filled conical microchannels. The work confirms that microfluidic iontronic circuits can achieve the full complement of Boolean logic operations required for universal computing, without any electronic components inside the fluidic domain.[31][32] **LINK** https://pubs.rsc.org/en/content/articlehtml/2025/sm/d5sm00601e https://arxiv.org/html/2503.13386v1