Path E - Chemical Information Processing


image cip path

The Chemical Information Processing Path (CIP) uses chemical properties of substances (composition, physical state, concentration, etc.) as carriers of information. The unconventional approach is to process this chemical information in a controllable, integrated, massively parallel, microfluidic environment with various functional composition elements. Implemented with CMOS, this technology has the potential to revolutionize many processes involving feedback loops of chemical information (e.g., the synthesis of matter with designed properties) that are nowadays slow and manual and in doing so, open up completely new application domains.

Overall Goal + Justification

The Path aims to advance electronics by implementing a new functionality: the processing of chemical information. Looking to nature, we note that CIP with implemented decision-making, selection processes and adaptability to unpredictable events are basic principles (related to CIP) in reproducing and further developing the incredible diversity of life. Breaking it down to the comparably simple task of developing a retro-synthetic approach of a single complex natural chemical substance, the enormous effort involved becomes clear: the task requires

  • a multitude of individual reaction steps each in need of reaction condition optimization;
  • decisions determining in which direction to further proceed;
  • extensive brain and man power to combine scientific knowledge,
  • and knowledge-based decision making with labor and time intensive experiments with often unpredictable outcomes.

A perfect tool to overcome these limitations would be a technical platform that processes chemical information in the form of matter figuratively comparable with today’s microprocessors processing electronic information. A highly integrated CIP chip could perform not only hundreds or thousands of chemical reactions simultaneously, but would also provide the capabilities to perform the analysis tasks as well as the required decision making by means of integrated closed loop control mechanisms, e.g., with chemical transistors combining both chemical sensor and actuator properties in a single component.

Such systems have the potential to reduce the processing time from years to days, and are able to minimize the consumption of energy and chemicals, and drastically improve the reliability of the processes. Furthermore, the above-indicated natural CIP networks have a robust performance, which includes complex trade-offs between energy requirements, transport efficiency, and fault tolerance. Utilizing the underlying principles of a CIP chip, we could generate a tool capable of optimizing the balance of cost, efficiency, and resilience for critical transport problems of natural or designed complex networks. This may enable the exploitation of complex biological processes to a much greater extent, such as in the case of resource scarcity or disasters.

Research Approach


From a general point of view, the ideal CIP “microprocessor” consists of an active polymer substrate comparable with active silicon substrate-based microprocessors, which interact with the information carrier “electronic charge”. In CIP, an active-substrate material is required capable of interacting with an information carrier such as substance concentration. The only realistic microfluidic active-substrate platform is based on stimuli-responsive hydrogels. These exceptional materials are in a critical swelling equilibrium, which depends on the free enthalpy of mixing polymer network and swelling agent, and the elasticity of the polymer chains (Flory-Rehner theory). Even small changes in environmental parameters, e.g., small changes of a certain solvent concentration, can lead to a so-called volume phase transition, which is a drastic change of the swelling degree of the hydrogel.

The only working hydrogel-based microsystems platform originates from Dresden and has been developed as result of the former collaborative research center, SFB 287 ”Reactive Polymers“. We have created a wide range of microfluidic basic components including microvalves, micropumps and chemical sensors. Furthermore, we have successfully developed a fabrication technology to monolithically integrate thousands of hydrogel-based components into the microchip by using UV lithography and created principles to electronically control each of the thousands of components individually.

Our concept is the only other LSI technology besides micropneumatics suitable for microfluidics. Unlike micropneumatics however, our active-substrate systems are able to interact autonomously with chemical information. As an essential prerequisite for the CIP, we invented two basic types of chemostat valves (chemical transistors), which combine the characteristics of actuator and chemical sensor. In contrast to electronic transistors, chemical transistors regulate a liquid flow depending upon a special concentration with the concentration threshold being adjustable e.g., by temperature control.

The response time of hydrogel-based microfluidic components is in the range of hundreds of milliseconds to a few seconds and complies with the time requirements of diffusion-based reactions. Long-term expertise in the field of synthesis and functionalization of hydrogels, their use in MEMS, chemical sensors and material modeling exists in Dresden.

This preliminary work is the fundament of the current Path and creates the physical, material and theoretical base of an active-substrate microprocessor platform for chemical information processing. The Path is divided into four Research Modules (see table). It integrates the expertise of the new Strategic Professor Adaptive Networks (SP AN). Furthermore, a new RGL Chemical Information Processing Systems will be created for exploring CIP from the device level up.

Recent Achievements

The world's first Chemical Microprocessor


  • 2017

  • Sebastian Haefner, Rene Koerbitz, Philipp Frank, Martin Elstner, Andreas Richter, "High Integration of Microfluidic Circuits Based on Hydrogel Valves for MEMS Control", In Advanced Materials Technologies, Wiley, vol. 3, no. 1, pp. 1700108, Nov 2017. [doi] [Bibtex & Downloads]
  • Franke, M.and Leubner, S.and Dubavik, A.and George, A.and Savchenko, T.and Pini, C.and Frank, P.and Melnikau, D.and Rakovich, Y.and Gaponik, N.and Eychm"uller, A.and Richter, A., "Immobilization of pH-sensitive CdTe Quantum Dots in a Poly(acrylate) Hydrogel for Microfluidic Applications", In Nanoscale Research Letters, vol. 12, no. 1, pp. 314, Apr 2017. [doi] [Bibtex & Downloads]
  • Samata Chaudhuri, Till Korten, Stefan Diez, "Tetrazine–trans-cyclooctene Mediated Conjugation of Antibodies to Microtubules Facilitates Subpicomolar Protein Detection", In Bioconjugate Chemistry, American Chemical Society (ACS), vol. 28, no. 4, pp. 918-922, Mar 2017. [doi] [Bibtex & Downloads]
  • Philipp Frank, David Gräfe, Christopher Probst, Sebastian Haefner, Martin Elstner, Dietmar Appelhans, Dietrich Kohlheyer, Brigitte Voit, Andreas Richter, "Autonomous Integrated Microfluidic Circuits for Chip-Level Flow Control Utilizing Chemofluidic Transistors", In Advanced Functional Materials, Wiley Online Library, vol. 27, no. 30, pp. 1700430, 2017. [Bibtex & Downloads]
  • Sebastian Haefner, Philipp Frank, Enrico Langer, Denise Gruner, Ulrike Schmidt, Martin Elstner, Gerald Gerlach, Andreas Richter, "Chemically controlled micro-pores and nano-filters for separation tasks in 2D and 3D microfluidic systems", In RSC Adv., Royal Society of Chemistry (RSC), vol. 7, no. 78, pp. 49279–49289, 2017. [doi] [Bibtex & Downloads]
  • 2016

  • Frank, Philipp AND Schreiter, Joerg AND Haefner, Sebastian AND Paschew, Georgi AND Voigt, Andreas AND Richter, Andreas, "Integrated Microfluidic Membrane Transistor Utilizing Chemical Information for On-Chip Flow Control", In PLoS ONE, Public Library of Science, vol. 11, no. 8, pp. 1-17, 08/2016. [doi] [Bibtex & Downloads]
  • Andreas Voigt, Andreas Richter, "Polymer Gels as EAPs: Fundamentals", In Electromechanically Active Polymers: A Concise Reference, Springer, pp. 3–26, 2016. [Bibtex & Downloads]
  • Philipp J Mehner, Sebastian Haefner, Markus Franke, Andreas Voigt, Uwe Marschner, Andreas Richter, "Finite Element Model of a Hydrogel-Based Micro-Valve", In Proceeding: ASME 2016 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, pp. V002T03A016–V002T03A016, 2016. [Bibtex & Downloads]
  • Adrian Ehrenhofer, Gert Bingel, Georgi Paschew, Marcus Tietze, Raoul Schröder, Andreas Richter, Thomas Wallmersperger, "Permeation control in hydrogel-layered patterned PET membranes with defined switchable pore geometry–Experiments and numerical simulation", In Sensors and Actuators B: Chemical, Elsevier, vol. 232, pp. 499–505, 2016. [Bibtex & Downloads]
  • Martin Elstner, Andreas Richter, "Polymer Gels as EAPs: Applications", In Electromechanically Active Polymers: A Concise Reference, Springer, pp. 83–99, 2016. [Bibtex & Downloads]
  • Banu Iyisan, Jörg Kluge, Petr Formanek, Brigitte Voit, Dietmar Appelhans, "Multifunctional and dual-responsive polymersomes as robust nanocontainers: design, formation by sequential post-conjugations, and pH-controlled drug release", In Chemistry of Materials, ACS Publications, vol. 28, no. 5, pp. 1513–1525, 2016. [Bibtex & Downloads]
  • Georgi Paschew, Jörg Schreiter, Andreas Voigt, Cesare Pini, Joseph Páez Chávez, Merle Allerdißen, Uwe Marschner, Stefan Siegmund, René Schüffny, Frank Jülicher, Andreas Richter, "Autonomous Chemical Oscillator Circuit Based on Bidirectional Chemical-Microfluidic Coupling", In Advanced Materials Technologies, vol. 1, no. 1, pp. 1600005–n/a, 2016. [doi] [Bibtex & Downloads]
  • Adrian Ehrenhofer, Thomas Wallmersperger, Andreas Richter, "Simulation of controllable permeation in PNIPAAm coated membranes", vol. 9800, pp. 980016-980016-13, 2016. [doi] [Bibtex & Downloads]
  • M. Franke, I. Slowik, G. Paschew, U. Merkel, H. Fröb, K. Leo, A. Richter, "Electrically tunable, optical microcavity based on metallized and ultra-soft PDMS gel", vol. 9798, pp. 979832-979832-9, 2016. [doi] [Bibtex & Downloads]
  • Sebastian Haefner, Mathias Rohn, Philipp Frank, Georgi Paschew, Martin Elstner, Andreas Richter, "Improved PNIPAAm-Hydrogel Photopatterning by Process Optimisation with Respect to UV Light Sources and Oxygen Content" , In Gels, vol. 2, no. 1, 2016. [doi] [Bibtex & Downloads]
  • Adrian Ehrenhofer, Gert Bingel, Georgi Paschew, Marcus Tietze, Raoul Schröder, Andreas Richter, Thomas Wallmersperger, "Permeation control in hydrogel-layered patterned PET membranes with defined switchable pore geometry – Experiments and numerical simulation", In Sensors and Actuators B: Chemical, vol. 232, pp. 499 - 505, 2016. [doi] [Bibtex & Downloads]
  • Philipp Frank, Sebastian Haefner, Martin Elstner, Andreas Richter, "Fully-Programmable, Low-Cost, “Do-It-Yourself” Pressure Source for General Purpose Use in the Microfluidic Laboratory" , In Inventions, vol. 1, no. 2, 2016. [doi] [Bibtex & Downloads]
  • Joseph Páez Chávez, Andreas Voigt, Jörg Schreiter, Uwe Marschner, Stefan Siegmund, Andreas Richter, "A new self-excited chemo-fluidic oscillator based on stimuli-responsive hydrogels: Mathematical modeling and dynamic behavior", In Applied Mathematical Modelling, vol. 40, no. 23–24, pp. 9719 - 9738, 2016. [doi] [Bibtex & Downloads]
  • A. T. Krause, S. Zschoche, M. Rohn, C. Hempel, A. Richter, D. Appelhans, B. Voit, "Swelling behavior of bisensitive interpenetrating polymer networks for microfluidic applications", In Soft Matter, The Royal Society of Chemistry, vol. 12, pp. 5529-5536, 2016. [doi] [Bibtex & Downloads]
  • Sebastian Haefner, Philipp Frank, Martin Elstner, Johannes Nowak, Stefan Odenbach, Andreas Richter, "Smart hydrogels as storage elements with dispensing functionality in discontinuous microfluidic systems", In Lab Chip, The Royal Society of Chemistry, vol. 16, pp. 3977-3989, 2016. [doi] [Bibtex & Downloads]
  • Bernhard Ferse, Luis Pedrero, Marcus Tietze, Andreas Richter, "Polymer Gels as EAPs: How to Start Experimenting with Them", In Electromechanically Active Polymers: A Concise Reference, Springer, pp. 101–127, 2016. [Bibtex & Downloads]
  • Irma Slowik, Nils M. Kronenberg, Markus Franke, Axel Fischer, Andreas Richter, Malte C. Gather, Karl Leo, "Elastomer based electrically tunable, optical microcavities", In Applied Physics Letters, vol. 109, no. 17, pp. 171104, 2016. [doi] [Bibtex & Downloads]
  • Till Korten, Samata Chaudhuri, Elena Tavkin, Marcus Braun, Stefan Diez, "Kinesin-1 Expressed in Insect Cells Improves Microtubule in Vitro Gliding Performance, Long-Term Stability and Guiding Efficiency in Nanostructures", In IEEE transactions on nanobioscience, IEEE, vol. 15, no. 1, pp. 62–69, 2016. [Bibtex & Downloads]
  • 2015

  • Chengzhou Zhu, Dan Wen, Susanne Leubner, Martin Oschatz, Wei Liu, Matthias Holzschuh, Frank Simon, Stefan Kaskel, Alexander Eychmüller, "Nickel cobalt oxide hollow nanosponges as advanced electrocatalysts for the oxygen evolution reaction", In Chemical Communications, Royal Society of Chemistry, vol. 51, no. 37, pp. 7851–7854, 2015. [Bibtex & Downloads]
  • Jeremias Epperlein, Stefan Siegmund, Petr Stehlík, "Evolutionary games on graphs and discrete dynamical systems", In Journal of Difference Equations and Applications, Taylor & Francis, vol. 21, no. 2, pp. 72–95, 2015. [doi] [Bibtex & Downloads]
  • C. Köhler, R. Backofen, A. Voigt, "Relaxation of curvature-induced elastic stress by the Asaro-Tiller-Grinfeld instability", In EPL (Europhysics Letters), IOP Publishing, vol. 111, no. 4, pp. 48006, 2015. [Bibtex & Downloads]
  • Soheil Hatami, Christian Würth, Martin Kaiser, Susanne Leubner, Stefanie Gabriel, Lydia Bahrig, Vladimir Lesnyak, Jutta Pauli, Nikolai Gaponik, Alexander Eychmüller, others, "Absolute photoluminescence quantum yields of IR26 and IR-emissive Cd 1- x Hg x Te and PbS quantum dots–method-and material-inherent challenges", In Nanoscale, Royal Society of Chemistry, vol. 7, no. 1, pp. 133–143, 2015. [Bibtex & Downloads]
  • Philipp Frank, Sebastian Haefner, Georgi Paschew, Andreas Richter, "Rounding of Negative Dry Film Resist by Diffusive Backside Exposure Creating Rounded Channels for Pneumatic Membrane Valves", In Micromachines, vol. 6, no. 11, pp. 1588–1596, 2015. [doi] [Bibtex & Downloads]
  • Previous Years

  • Andreas Voigt, Uwe Marschner, Andreas Richter, "Multiphysics equivalent circuit of a thermally controlled hydrogel microvalve", In Journal of Intelligent Material Systems and Structures, pp. 1045389X16685445. [doi] [Bibtex & Downloads]
  • Andreas Voigt, Weichang Feng, Merle Allerdißen, Luis Pedrero, Andreas Richter, "Chemical Transistors as a Basis for Chemical Computing", In Unconventional Computation and Natural Computation, pp. 28. [Bibtex & Downloads]