Dr. Rainer Fasching is a technology executive and a consulting associate professor at Stanford University, where he teaches advanced electrochemical energy storage and sensor technologies. He has over 20 years of experience in electrochemical devices, micro fabrication technologies, and industrial product development. His work has been centered on the physics, materials and fabrication technologies of electrochemical systems such as sensors, batteries and associated materials, and fuel cells. Currently he has been leading the development of advanced energy storage technologies from concept to product at top tier startup companies. He holds over 30 issued and/or published patents and has authored more than 60 publications.
Adjunct Professor, Mechanical Engineering
- Nickel Silicide Nanowire Arrays for Anti-Reflective Electrodes in Photovoltaics ADVANCED FUNCTIONAL MATERIALS 2012; 22 (17): 3650-3657
Three-dimensional biodegradable microscaffolding: Scaffold characterization and cell population at single cell resolution
2011; 7 (9): 3325-3335
Engineering artificial tissue scaffolds with a similar organization to that of the natural tissue is a key element to the successful recapitulation of function. However, three-dimensional (3-D) fabrication of tissue scaffolds containing complex microarchitectures still remains a challenge. In addition, little attention has been paid to the issue of how to incorporate cells within 3-D tissue scaffolds that contain precisely engineered architectures. Here we report a 3-D biodegradable microscaffolding (3D-BMS) technology and its process characterization as well as a microscale cellular loading technology as an efficient way to massively populate biodegradable polymers with cells at single cell resolution. In this study a particular emphasis was given to characterization of the material properties of the biodegradable polymers undergoing the 3D-BMS processes. Optimal process conditions were identified in order to avoid any unwanted change in material properties, such as crystallinity and scaffold strength, that have a direct impact on the degradation speed and physical integrity of the constructed scaffolds. For precise control of the cell distribution within the microstructured scaffolds a high precision microsieve structure was designed to localize rat hepatocytes and human articular chondrocytes in the biodegradable polymers. Cell suspensions were passed at a predetermined flow rate through biodegradable polymer layers that contained tapered microholes in a massively parallel process. This high resolution cell seeding method allows accurate manipulation of cell placement in thin layers of biodegradable polymers.
View details for DOI 10.1016/j.actbio.2011.05.011
View details for Web of Science ID 000294040900009
View details for PubMedID 21640854
In vivo O-2 measurement inside single photosynthetic cells
2011; 33 (8): 1675-1681
The oxygen evolution of single cells was investigated using a nano-probe with an ultra-micro electrode (UME) in a submicron sized system in combination with a micro-fluidic system. A single cell was immobilized in the micro-fluidic system and a nano-probe was inserted into the cytosolic space of the single cell. Then, the UME was used for an in vivo amperometric experiment at a fixed potential and electrochemical impedance spectroscopy to detect oxygen evolution of the single cell under various light intensities.
View details for DOI 10.1007/s10529-011-0604-x
View details for Web of Science ID 000293752000025
View details for PubMedID 21476096
Direct Extraction of Photosynthetic Electrons from Single Algal Cells by Nanoprobing System
2010; 10 (4): 1137-1143
There are numerous sources of bioenergy that are generated by photosynthetic processes, for example, lipids, alcohols, hydrogen, and polysaccharides. However, generally only a small fraction of solar energy absorbed by photosynthetic organisms is converted to a form of energy that can be readily exploited. To more efficiently use the solar energy harvested by photosynthetic organisms, we evaluated the feasibility of generating bioelectricity by directly extracting electrons from the photosynthetic electron transport chain before they are used to fix CO(2) into sugars and polysaccharides. From a living algal cell, Chlamydomonas reinhardtii, photosynthetic electrons (1.2 pA at 6000 mA/m(2)) were directly extracted without a mediator electron carrier by inserting a nanoelectrode into the algal chloroplast and applying an overvoltage. This result may represent an initial step in generating "high efficiency" bioelectricity by directly harvesting high energy photosynthetic electrons.
View details for DOI 10.1021/nl903141j
View details for Web of Science ID 000276557100007
View details for PubMedID 20201533
Open micro-fluidic system for atomic force microscopy-guided in situ electrochemical probing of a single cell
LAB ON A CHIP
2008; 8 (9): 1460-1467
Ultra-sharp nano-probes and customized atomic force microscopy (AFM) have previously been developed in our laboratory for in situ sub-cellular probing of electrochemical phenomena in living plant cells during their photosynthesis. However, this AFM-based electrochemical probing still has numerous engineering challenges such as immobilization of the live cells, compatibility of the immobilization procedure with AFM manipulation of the probe, maintenance of biological activity of the cells for an extended time while performing the measurements, and minimization of electrochemical noise. Thus, we have developed an open micro-fluidic channel system (OMFC) in which individual cells can be immobilized in micro-traps by capillary flow. This system affords easy AFM access and allows for maintenance of the cells in a well-defined chemical environment, which sustains their biological activity. The use of micro-channels for making the electrochemical measurements significantly reduces parasitic electrical capacitances and allows for current detection in the sub-pico-ampere range at high signal bandwidths. The OMFC was further studied using simulation packages for optimal design conditions. This system was successfully used to measure light-dependent oxidation currents of a few pico-amperes from the green alga Chlamydomonas reinhardtii.
View details for DOI 10.1039/b803450h
View details for Web of Science ID 000259676000007
View details for PubMedID 18818800
Solid oxide fuel cell with corrugated thin film electrolyte
2008; 8 (8): 2289-2292
A low temperature micro solid oxide fuel cell with corrugated electrolyte membrane was developed and tested. To increase the electrochemically active surface area, yttria-stabilized zirconia membranes with thickness of 70 nm were deposited onto prepatterned silicon substrates. Fuel cell performance of the corrugated electrolyte membranes released from silicon substrate showed an increase of power density relative to membranes with planar electrolytes. Maximum power densities of the corrugated fuel cells of 677 mW/cm2 and 861 mW/cm2 were obtained at 400 and 450 degrees C, respectively.
View details for DOI 10.1021/nl800977z
View details for Web of Science ID 000258440700030
View details for PubMedID 18605702
Controlled release of growth factors on allograft bone in vitro
5th Musculoskeletal Transplant Foundation Symposium
SPRINGER. 2008: 1905–11
Allografts are important alternatives to autografts for treating defects after major bone loss. Bone growth factors have both local autocrine and paracrine effects and regulate the growth, proliferation, and differentiation of osteoprogenitor cells. To study the effects of prolonged, continuous, local delivery of growth factors on bone growth, we developed a new microelectromechanical system (MEMS) drug delivery device. Bone marrow cells from mice were seeded on mouse allograft discs and cultured in osteogenic media with osteogenic protein 1 (OP-1) and/or basic fibroblast growth factor (FGF-2) delivered from MEMS devices for 6 weeks. We monitored bone formation by changes of bone volume using micro-CT scanning and release of osteocalcin using ELISA. The data suggest the MEMS devices delivered constant concentrations of OP-1 and FGF-2 to the media. Bone marrow cells grew on the allografts and increased bone volume. Addition of OP-1 increased bone formation whereas FGF-2 decreased bone formation. Local delivery of growth factors over a prolonged period modulated the differentiation of osteoprogenitor cells on allograft bone.
View details for DOI 10.1007/s11999-008-0290-8
View details for PubMedID 18509711
- Nanoscale probe system for cell-organelle analysis SENSORS AND ACTUATORS B-CHEMICAL 2008; 130 (1): 249-257
- Reversible oxidation of spinach ferredoxin at surface-modified electrodes JOURNAL OF THE ELECTROCHEMICAL SOCIETY 2008; 155 (10): B1008-B1012
Biodegradable micro-osmotic pump for long-term and controlled release of basic fibroblast growth factor
JOURNAL OF CONTROLLED RELEASE
2007; 124 (1-2): 98-105
Microelectromechanical system (MEMS) technology not only provides the possibility of integration of multiple functions but also enables more precise control of dosing of therapeutic agents when the therapeutic window is very limited. Local delivery of basic fibroblast growth factor (bFGF) over a specific dose and time course is critical for mesenchymal tissue regeneration. However, bFGF is degraded quickly in vivo and difficulty of controlling the dose level impedes its effective use in angiogenesis and tissue regeneration. We constructed biodegradable micro-osmotic pumps based on MEMS technology for long-term controlled release of bFGF. The devices were constructed by micro-molding and thermal assembly of 85/15 poly(L-lactide-co-glycolide) sheets. The release of bFGF was regulated at 40 ng/day for four weeks; bioactivity was assessed by monitoring the growth of 3T3 fibroblasts. The proposed devices can be further miniaturized and used for the delivery of multiple therapeutic agents at the individual releasing schedules.
View details for DOI 10.1016/j.jconrel.2007.08.024
View details for PubMedID 17904240
Fabrication of multi-layered biodegradable drug delivery device based on micro-structuring of PLGA polymers
2007; 9 (6): 845-853
A programmable and biodegradable drug delivery device is desirable when a drug needs to be administered locally. While most local drug delivery devices made of biodegradable polymers relied on the degradation of the polymers, the degradation-based release control is often limited by the property of the polymers. Thus, we propose micro-geometry as an alternative measure of controlling drug release. The proposed devices consist of three functional layers: diffusion control layer via micro-orifices, diffusion layer, and drug reservoir layers. A micro-fabrication technology was used to shape an array of micro-orifices and micro-cavities in 85/15PLGA layers. A thin layer of fast degrading 50/50PLGA was placed as the diffusion layer between the 85/15PLGA layers to prevent any burst-type release. To modulate the release of the devices, the dimension and location of the micro-orifices were varied and the responding in vitro release response of tetracycline was monitored over 2 weeks. The release response to the different micro-geometry was prominent and further analyzed by FEM simulation. Comparison of the experiments to the simulated results identified that the variation of micro-geometry influenced also the volume-dependent degradation rate and induced the osmotic pressure.
View details for DOI 10.1007/s10544-007-9097-8
View details for Web of Science ID 000250462200009
View details for PubMedID 17577671
The construction of three-dimensional micro-fluidic scaffolds of biodegradable polymers by solvent vapor based bonding of micro-molded layers
2007; 28 (6): 1174-1184
It is increasingly important to control cell growth into and within artificial scaffolds. Tissues such as skin, blood vessels, and cartilage have multi-layer structures with different cells in each layer. With the aid of micro-fabrication technology, a novel scaffolding method for biodegradable polymers such as polylactic acid (PLA), polyglycolic acid (PGA), and the copolymers poly(lactide-co-glycolide)(PLGA), was developed to construct three-dimensional multi-layer micro-fluidic tissue scaffolds. The method emphasizes micro-fluidic interconnections between layers within the scaffolds and maintenance of high-resolution geometries during the bonding process for the creation of multi-layered scaffolds. Micro-holes (10-100 microm), micro-channels, and micro-cavities were all created by micro-molding. Solvent-vapor based bonding of micro-molded layers preserved 20 microm sized structures. Sample scaffolds were constructed for purposes such as channel-directed cell growth and size-based cell sorting. Further extension of these techniques to create a micro-vascular network within or between layers is possible. Culturing of human coronary artery endothelial cells (HCAECs) on the sample scaffolds demonstrated the biocompatibility of the developed process and the strong influence of high-resolution micro-geometries on HCAEC growth.
View details for DOI 10.1016/j.biomaterials.2006.11.002
View details for Web of Science ID 000243219000028
View details for PubMedID 17126395
- High-performance ultrathin solid oxide fuel cells for low-temperature operation JOURNAL OF THE ELECTROCHEMICAL SOCIETY 2007; 154 (1): B20-B24
AFM/EC nano probing of single cells and organelles
6th IEEE Sensors Conference
IEEE. 2007: 699–702
View details for Web of Science ID 000254563600177
- Microfabrication technology of biodegradable polymers for interconnecting microstructures JOURNAL OF MICROELECTROMECHANICAL SYSTEMS 2006; 15 (6): 1457-1465
- Nanoscale electrochemical probes for single cell analysis 31st International Conference on Micro- and Nano-Engineering ELSEVIER SCIENCE BV. 2006: 1638–41
- Nanofabrication of electrochemical planar probes for single cell analysis Conference on Micromachining and Microfabrication Process Technology XI SPIE-INT SOC OPTICAL ENGINEERING. 2006
- Cantilever tip probe arrays for simultaneous SECM and AFM analysis 10th International Meeting on Chemical Sensors ELSEVIER SCIENCE SA. 2005: 964–72
- Ultra-sharp high-aspect-ratio probe array for SECM and AFM analysis Smart Structures and Materials 2004 Conference SPIE-INT SOC OPTICAL ENGINEERING. 2004: 431–442
Fabrication of an electrochemical tip-probe system embedded in SiNx-cantilevers for simultaneous SECM and AFM analysis
Conference on Micromachining and Microfabrication Process Technology IX
SPIE-INT SOC OPTICAL ENGINEERING. 2004: 53–64
View details for Web of Science ID 000189447200008
- A miniaturized amperometric CO2 sensor based on dissociation of copper complexes 9th International Meeting on Chemical Sensors ELSEVIER SCIENCE SA. 2003: 197–204
High-density multi-layer connection technology for MEMS and CMOS applications
Conference on Smart Sensors, Actuators, and MEMS
SPIE-INT SOC OPTICAL ENGINEERING. 2003: 536–542
View details for Web of Science ID 000184053200061
A pencil probe system for electrochemical analysis and modification in nanometer dimensions
Conference on Smart Sensors, Actuators, and MEMS
SPIE-INT SOC OPTICAL ENGINEERING. 2003: 128–135
View details for Web of Science ID 000184053200016