Grzegorz Bubak

Istituto Italiano di Tecnologia | IIT

The reaction kinetics between like-charged compounds in water is extremely slow due to Coulomb repulsions. Here, we demonstrate that by screening these interactions and, in consequence, increasing the local concentration of reactants, we boost the reactions by many orders of magnitude. The reaction between negatively charged Coenzyme A molecules ac...

The equilibrium constant (K) of biochemical complex formation in aqueous buffers with high concentration (>20 wt %) of nonionic compounds can vary by orders of magnitude in comparison with the K in a pure buffer. The precise molecular mechanisms of these profound changes are not known. Herein, we show up to a 1000-fold decrease of the K value of DN...

Understanding the mobility of nano-objects in the eukaryotic cell nucleus, at multiple length-scales, is essential for dissecting nuclear structure-function relationships both in space and in time. Here, we demonstrate, using single-molecule fluorescent correlation spectroscopies, that motion of inert probes (proteins, polymers, or nanoparticles) w...

The efficient delivery of drugs to cells depends on their diffusion through the extracellular matrix (ECM) of tissues. Here we present a study of diffusion of nanoprobes of radius from 1 nm to over 100 nm in the ECM of spheroids of three cell types (HeLa, MCF-7 and fibroblasts). We quantified nanoparticle transport in spheroids’ proliferating zone....

Intrinsic molecular brightness (MB) is a number of emitted photons per second per molecule. When a substrate labeled by a fluorophore and a second unlabeled substrate form a complex in solution, the MB of the fluorophore changes. Here we use this change to determine the equilibrium constant (K) for the formation of the complex at pM concentrations....

Biophotovoltaics is a young and dynamic field of green nanotechnology which utilizes photosynthetic organisms, such as cyanobacteria and algae, their photosynthetically active biological membranes, or the components of the photosynthetic apparatus to harness solar energy and convert it into electricity and solar fuels. The attractiveness of this ap...

This chapter summarizes properties and characterization of a broad range of functional polymeric materials. The attention is drawn toward hybrid polymers for electroactive applications. The first section describes photoactive polymer materials for optoelectronics with a focus on the properties and characterization techniques. The second section exa...

Carbon nanotube actuators possess the requirements to be used in soft robotic applications as they are lightweight, simple to assemble and can operate at low voltage. However, there is still a need to further enhance their performances—in particular strain and blocking force—in order to render their implementation in devices more viable. In this st...

Bucky gel actuators are typically fabricated by having an electrolyte layer sandwiched by two carbon nanotubes electrodes. They possess outstanding electrical and mechanical properties thanks to their composition, which make them very attractive for robotics applications. Even though carbon nanotube electrodes have been extensively studied in the r...

Simple fabrication, high power-to-weight and power-to-volume ratios, and the ability to operate in open air at low voltage make the ionic electroactive polymer actuators highly attractive for haptic applications. Whenever a direct tactile stimulation of the skin is involved, electrical and chemical insulation as well as a long term stability of the...

Ionic liquid/carbon nanotube based actuators have been constantly improved in recent years owing to their suitability for applications related to human-machine interaction and robotics thanks to their light-weight and low voltage operation. However, while great attention has been paid to the development of better electrodes and electrolytes, no ade...

Recently, materials that can convert electrical energy into mechanical work have drawn great attention. Applications in robotics, tactile or optical displays and microelectrochemical systems are currently investigated. Likewise, interest in actuators devices is increasing toward applications where low voltage and low weight properties are required....

An ideal plastic actuator for haptic applications should generate a relatively large displacement (minimum 0.2-0.6 mm, force (~50 mN/cm2) and a fast actuation response to the applied voltage. Although many different types of flexible, plastic actuators based on electroactive polymers (EAP) are currently under investigation, the ionic EAPs are the o...

There is a lack of safe, lightweight, low-voltage actuators that can be used in haptic applications. One of the possible solutions is ionic electroactive polymer actuator - the only one among electroactive polymers that can be operated at low voltage in air. In this paper we present the carbon nanotubes based plastic actuators that we are currently...

Alloplastic bone substitute materials are raising some more interest as an alternative for autologic transplants and xenogenic materials especially in oral surgery over the last few years. These non-immunogenic and completely resorbable biomaterials are the basis for complete and predictable guided bone regeneration. In the majority of cases, such...

The main objective of the work was to design and fabricate an injectable biomaterial with osteoconductive properties for bone augmentation and potential to be used in dental applications in peri-implant therapy concerning guided bone regeneration. For this purpose, a self-setting biomaterial consisting of chitosan/ tricalcium phosphate microparticl...