Components with highly sensitive surfaces are used in automotive, semiconductor and display technologies as well as for complex optical lens systems. During the production, these parts often have to be handled many times by pick-and-place processes. Each pick-up and release with conventional gripping systems involves the risk of either contamination of the surfaces with residues from transportation adhesives, or damage due to mechanical gripping. Suction cup systems diminish residues, but fail in a vacuum or on rough surfaces. Researchers at the Leibniz Institute for New Materials (INM) have now enhanced the Gecko adhesion principle such that adhesion can be switched on and off in vacuum. The researchers from the INM will be presenting their results from 13 to 17 April 2015 in Hall 2 at the stand B46 of the Hannover Messe in the context of the leading trade fair for R & D and Technology Transfer. 
Switchable adhesion principle enables damage-free handling of sensitive devices even in vacuum; (Image: Uwe Bellhäuser) "Artificially produced microscopic pillars, so-called gecko structures, adhere to various items. By manipulating these pillars, the adhesion can be switched on and off. Thus, items can be lifted and released quickly and precisely," Karsten Moh from the Program Division Functional Microstructures explains. "This technique is particularly interesting in vacuum, as suction cups fail there," says Moh. With the currently developed adhesion system, adhesive forces of more than 1 Newton per square centimeter can be achieved on smooth surfaces." In our tests, the system has proved successful even after 100,000 cycles", the upscaling expert Moh says. Even slightly rough surfaces can be handled reliably. The developers now focus on increasing the adhesion force to lift and release large components and heavy materials in an energy-efficient way. Furthermore the development group works on the gripping of objects with curved surfaces without leaving residues. Additionally, the scientists also focus on developing other triggers for switching the adhesion like light, magnetic field, electric field or changes in temperature. INM conducts research and development to create new materials – for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM: New materials for energy application, new concepts for medical surfaces, new surface materials for tribological applications and nano safety and nano bio. Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces.
Switchable adhesion principle enables damage-free handling of sensitive devices even in vacuum; (Image: Uwe Bellhäuser) "Artificially produced microscopic pillars, so-called gecko structures, adhere to various items. By manipulating these pillars, the adhesion can be switched on and off. Thus, items can be lifted and released quickly and precisely," Karsten Moh from the Program Division Functional Microstructures explains. "This technique is particularly interesting in vacuum, as suction cups fail there," says Moh. With the currently developed adhesion system, adhesive forces of more than 1 Newton per square centimeter can be achieved on smooth surfaces." In our tests, the system has proved successful even after 100,000 cycles", the upscaling expert Moh says. Even slightly rough surfaces can be handled reliably. The developers now focus on increasing the adhesion force to lift and release large components and heavy materials in an energy-efficient way. Furthermore the development group works on the gripping of objects with curved surfaces without leaving residues. Additionally, the scientists also focus on developing other triggers for switching the adhesion like light, magnetic field, electric field or changes in temperature. INM conducts research and development to create new materials – for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM: New materials for energy application, new concepts for medical surfaces, new surface materials for tribological applications and nano safety and nano bio. Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces.
Paclitaxel/Gemcitabine co-delivery inhibits pancreatic cancer. The study was led by Dr. Huan Meng, assistant adjunct professor of medicine, and Dr. Andre Nel, distinguished professor of medicine, both at the Jonsson Cancer Center. Pancreatic cancer, a devastating disease with a five-year survival rate of 5 percent, is difficult to detect early and symptoms do not usually appear until the disease is advanced. As a result, many people are not diagnosed until their tumors are beyond the effective limits of surgery, leaving chemotherapy as the only viable treatment option. The chemotherapy drug most often used for pancreas cancer is gemcitabine, but its impact is often limited. Recent research has found that combining gemcitabine with another drug called paclitaxel can improve the overall treatment effect. In the current method, Abraxane — a nano complex containing paclitaxel — and gemcitabine are given separately, which works to a degree, but because the drugs may stay in the body for different lengths of time, the combined beneficial effect is not fully synchronized. “The beauty of the silica nanoparticle technology is that gemcitabine and paclitaxel are placed together in one special lipid-coated nanoparticle at the exact ratio that makes them synergistic with one another when co-delivered at the cancer site, giving us the best possible outcome by using a single drug carrier,” Meng said. “This enables us to reduce the dose and maintain the combinatorial effect.” After the scientists constructed the silica nanoparticles, they suspended them in blood serum and injected them into mice that had human pancreas tumors growing under their skin. Other mice with tumors were given injections of saline solution (a placebo with no effect), gemcitabine (the treatment standard), and gemcitabine and Abraxane (an FDA-approved combination shown to improve pancreas cancer survival in humans). In the mice that received the two drugs inside the nanoparticle, pancreas tumors shrank dramatically compared with those in the other mice. Similar comparisons were made with mouse models, in which the human tumors were surgically implanted into the mice’s abdomens in order to more closely emulate the natural point of origin of pancreatic tumors and provide a better parallel to the tumors in humans. In these experiments, the tumors in the mice receiving silica nanoparticles shrank more than the comparative controls. Also, metastasis, or tumor spread, to nearby organs was eradicated in these mice. “Instead of just a laboratory proof-of-principle study of any cancer, we specifically attacked pancreatic cancer with a custom-designed nanocarrier,” said Nel, who is also associate director for research of the California NanoSystems Institute. “In our platform, the drugs are truly synergistic because we have control over drug mixing, allowing us to incorporate optimal ratios in our particles, making the relevance of our models very high and our results very strong.” Meng said the silica nanocarrier must still be refined for use in humans. The researchers hope to test the platform in human clinical trials within the next five years.