• Voiced actor Patchy Zomboss: Max Charles
  • Voiced actor Monkey Zomboss: Ariel Winter

The Upping Down 2Edit

The City of New York Patchy particle are micron- or nanoscale colloidal particles that are anisotropically patterned, either by modification of the particle surface chemistry ("enthalpic patches"),[1] through particle shape ("entropic patches"),[2] or both.[3] Patchy particles are used as a shorthand for modelling anisotropic colloids [1] and proteins [4] and for designing approaches to nanoparticle synthesis.[5] Patchy particles range in valency from two (Janus particles) or higher.

Self-assembly is a process in which a disordered system of pre-existing components forms an organized structure or pattern as a consequence of specific, local interactions among the components themselves, without external direction. When the constitutive components are molecules, the process is termed molecular self-assembly.

Self-assembly can be classified as either static or dynamic. In static self-assembly, the ordered state forms as a system approaches equilibrium, reducing its free energy. However, in dynamic self-assembly, patterns of pre-existing components organized by specific local interactions are not commonly described as "self-assembled" by scientists in the associated disciplines. These structures are better described as "self-organized", although these terms are often used interchangeably.

Self-assembly (SA) in the classic sense can be defined as the spontaneous and reversible organization of molecular units into ordered structures by non-covalent interactions. The first property of a self-assembled system that this definition suggests is the spontaneity of the self-assembly process: the interactions responsible for the formation of the self-assembled system act on a strictly local level—in other words, the nanostructure builds itself.

Self-assembled nano-structure is an object that appears as a result of ordering and aggregation of individual nano-scale objects guided by some physical principle.

Self-assembled nanostructure arises in the strong non-equilibrium conditions. The most famous example of self-assembly phenomenon is the occurrence of the life on Earth. It is plausible to hypothesize that it happens because the sun generates a strong temperate gradient in its environment. This general idea has been confirmed in the experiment of self-assembly of carbon nanotubes. At this point, one may argue that any chemical reaction driving atoms and molecules to assemble into larger structures, such as precipitation, could fall into the category of SA. However, there are at least three distinctive features that make SA a distinct concept.

Background Edit

SA extends the scope of chemistry aiming at synthesising products with order and functionality properties, extending chemical bonds to weak interactions and encompassing the self-assembly of NBBs on all length scales.[20] In covalent synthesis and polymerisation, the scientist links atoms together in any desired conformation, which does not necessarily have to be the energetically most favoured position; self-assembling molecules, on the other hand, adopt a structure at the thermodynamic minimum, finding the best combination of interactions between subunits but not forming covalent bonds between them. In self-assembling structures, the scientist must predict this minimum, not merely place the atoms in the location desired.

Another characteristic common to nearly all self-assembled systems is their thermodynamic stability. For SA to take place without intervention of external forces, the process must lead to a lower Gibbs free energy, thus self-assembled structures are thermodynamically more stable than the single, unassembled components. A direct consequence is the general tendency of self-assembled structures to be relatively free of defects. An example is the formation of two-dimensional superlattices composed of an orderly arrangement of micrometre-sized polymethylmethacrylate (PMMA) spheres, starting from a solution containing the microspheres, in which the solvent is allowed to evaporate slowly in suitable conditions. In this case, the driving force is capillary interaction, which originates from the deformation of the surface of a liquid caused by the presence of floating or submerged particles.[21]

These two properties—weak interactions and thermodynamic stability—can be recalled to rationalise another property often found in self-assembled systems: the sensitivity to perturbations exerted by the external environment. These are small fluctuations that alter thermodynamic variables that might lead to marked changes in the structure and even compromise it, either during or after SA. The weak nature of interactions is responsible for the flexibility of the architecture and allows for rearrangements of the structure in the direction determined by thermodynamics. If fluctuations bring the thermodynamic variables back to the starting condition, the structure is likely to go back to its initial configuration. This leads us to identify one more property of SA, which is generally not observed in materials synthesised by other techniques: reversibility.

SA is a process which is easily influenced by external parameters. This can make synthesis more problematic due to the many free parameters that require control. On the other hand, self assembly has the exciting advantage that a large variety of shapes and functions on many length scales can be obtained.[22]

Generally speaking, the fundamental condition needed for NBBs to self-assemble into an ordered structure is the simultaneous presence of long-range repulsive and short-range attractive forces.[23]

By choosing precursors with suitable physicochemical properties, it is possible to exert a fine control on the formation processes that produce complex structures. Clearly, the most important tool when it comes to designing a synthesis strategy for a material, is the knowledge of the chemistry of the building units. For example, it was demonstrated that it was possible to use diblock copolymers with different block reactivities in order to selectively embed maghemite nanoparticles and generate periodic materials with potential use as waveguides.[24]

In 2008, Advances in Colloid and Interface Science published a study in which it was concluded that every self-assembly process in reality presents a co-assembly, which makes the former term a misnomer of a kind.[25] The thesis is built on the concept of mutual ordering of the self-assembling system and its environment.

History Edit

Self-assembly processes can be observed in systems of macroscopic building blocks. These building blocks can be externally propelled[26] or self-propelled.[27] Since the 1950s, scientists have built self-assembly systems exhibiting centimeter-sized components ranging from passive mechanical parts to mobile robots.[28] For systems at this scale, the component design can be precisely controlled. For some systems, the components' interaction preferences are programmable. The self-assembly processes can be easily monitored and analyzed by the components themselves or by external observers.[29]

In April 2014, Skylar Tibbits of the Massachusetts Institute of Technology, demonstrated a combination of 3D printed plastic with a "smart material" that self-assembles in water.[30] Tibbits refers to this as "4D printing".

Trivia Edit

Monkeys are haplorhine primates, a group generally possessing tails and consisting of about 260 known living species. Many monkey species are tree-dwelling (arboreal), although there are species that live primarily on the ground, such as baboons. Most species are also active during the day (diurnal). Monkeys are generally considered to be intelligent, particularly Old World monkeys.

There are two major types of monkey: New World monkeys (platyrrhines) from South and Central America and Old World monkeys (catarrhines of the superfamily Cercopithecoidea) from Africa and Asia. Hominoid apes (consisting of gibbons, orangutans, gorillas, chimpanzees, and humans), which all lack tails, are also catarrhines but are not considered monkeys[citation needed], although often they or their ancestors are (which cladistically automatically implies homonoids are as well.)[3][4][5][6] (Tailless monkeys may be called "apes", incorrectly according to modern usage; thus the tailless Barbary macaque is sometimes called the "Barbary ape".) Simians ("monkeys") and tarsiers emerged within haplorrhines some 60 million years ago. New World monkeys and catarrhinemonkeys emerged within the simians some 35 millions years ago. Old World monkeys and Hominoidea emerged within the catarrhine monkeys some 25 millions years ago. Extinct basal simians such as Aegyptopithecus or Parapithecus [35-32 million years ago] are also considered monkeys by primatologists.

Lemurs, lorises, and galagos are not monkeys; instead they are strepsirrhineprimates. Like monkeys, tarsiers are haplorhine primates; however, they are also not monkeys.

Apes emerged within the catarrhines with the Old World monkeys as a sister group, so cladistically they are monkeys as well. However, traditionally apes are not considered monkeys, rendering this grouping paraphyletic. The equivalent monophyletic clade are the simians.


  • Suborder Strepsirrhini: lemurs, lorises, and galagos
  • Suborder Haplorhini: tarsiers, monkeys, and apes
    • Infraorder Tarsiiformes
      • Family Tarsiidae: tarsiers
    • Infraorder Simiiformes: simians
      • Parvorder Platyrrhini: New World monkeys
        • Family Callitrichidae: marmosets and tamarins (42 species)
        • Family Cebidae: capuchins and squirrel monkeys (14 species)
        • Family Aotidae: night monkeys (11 species)
        • Family Pitheciidae: titis, sakis, and uakaris (41 species)
        • Family Atelidae: howler, spider, and woolly monkeys (24 species)
      • Parvorder Catarrhini
        • Superfamily Cercopithecoidea
          • Family Cercopithecidae: Old World monkeys (135 species)
        • Superfamily Hominoidea: apes
          • Family Hylobatidae: gibbons ("lesser apes") (17 species)
          • Family Hominidae: great apes (including humans, gorillas, chimpanzees, and orangutans) (7 species)