Limitations of Self-Assembly at Temperature 1 David Doty, Matt - - PowerPoint PPT Presentation
Limitations of Self-Assembly at Temperature 1 David Doty, Matt - - PowerPoint PPT Presentation
Limitations of Self-Assembly at Temperature 1 David Doty, Matt Patitz, Scott Summers Department of Computer Science Iowa State University, Ames, IA, USA DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998 DNA Tile Self-Assembly Winfree, Ph.D.
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
X XY Z
Strength 0 Strength 1 Strength 2
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
- If tiles abut with
matching kinds of glue, then they bind with this glue’s strength.
X XY Z
Strength 0 Strength 1 Strength 2
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
- If tiles abut with
matching kinds of glue, then they bind with this glue’s strength.
- Tiles may have
labels.
Strength 0 Strength 1 Strength 2
X XY Z
R
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
- If tiles abut with
matching kinds of glue, then they bind with this glue’s strength.
- Tiles may have
labels.
- Tiles cannot be
rotated.
Strength 0 Strength 1 Strength 2
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
- If tiles abut with
matching kinds of glue, then they bind with this glue’s strength.
- Tiles may have
labels.
- Tiles cannot be
rotated.
Strength 0 Strength 1 Strength 2
X XY Z
R
- Finitely many tile types
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
- If tiles abut with
matching kinds of glue, then they bind with this glue’s strength.
- Tiles may have
labels.
- Tiles cannot be
rotated.
Strength 0 Strength 1 Strength 2
X XY Z
R
- Finitely many tile types
- Infinitely many of each
type available
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
- If tiles abut with
matching kinds of glue, then they bind with this glue’s strength.
- Tiles may have
labels.
- Tiles cannot be
rotated.
Strength 0 Strength 1 Strength 2
X XY Z
R
- Finitely many tile types
- Infinitely many of each
type available
- Assembly starts from a
seed tile (or seed assembly).
DNA Tile Self-Assembly Winfree, Ph.D. thesis, 1998
Extension of Wang tiling, 1961 Refined in Paul Rothemund’s Ph.D. thesis, 2001
- Tile = unit square
- Each side has glue
- f certain kind and
strength (0, 1, or 2).
- If tiles abut with
matching kinds of glue, then they bind with this glue’s strength.
- Tiles may have
labels.
- Tiles cannot be
rotated.
Strength 0 Strength 1 Strength 2
X XY Z
R
- Finitely many tile types
- Infinitely many of each
type available
- Assembly starts from a
seed tile (or seed assembly).
- A tile can attach to the
existing assembly if it binds with total strength at least equal to the “temperature”.
Tile Assembly Example
S L
c R c R
L
c R 1 n c
1
L
c R 1 n c
1
S
1 c c 1 n c
1
1 1 n n
1
n n c R
L
Edge binding strengths: 1 2
Cooperation is key to computing with Tile Assembly Model.
Tile Assembly Example
S L
c R c R
L
c R 1 n c
1
L
c R 1 n c
1
S
1 c c 1 n c
1
1 1 n n
1
n n c R
L
Edge binding strengths: 1 2
Cooperation is key to computing with Tile Assembly Model.
Both of these have to be present...
Tile Assembly Example
S L
c R c R
L
c R 1 n c
1
L
c R 1 n c
1
S
1 c c 1 n c
1
1 1 n n
1
n n c R
L
Edge binding strengths: 1 2
Cooperation is key to computing with Tile Assembly Model.
Both of these have to be present... ...before this can attach
Tile Assembly Example
S L
c R c R
L
c R 1 n c
1
S
1 c c 1 n c
1
1 1 n n
1
n n c R
L
Edge binding strengths: 1 2
n n
L
c R 1 c c c R 1 n c
1 L
n n n n 1 n c
1
1 c c n n c R
L
1 1 n n
1
n n 1 n c
1
n n n n c R
L L
n n n n n n 1 c c n n n n n n 1 n c
1
n n n n 1 1 n n
1
n n 1 c c 1 n c
1
n n n n 1 1 n n
1
n n 1 n c
1
1 1 n n
1
n n 1 1 n n
1
n n
Cooperation is key to computing with Tile Assembly Model.
Tile Assembly Example
S L
c R c R
L
c R 1 n c
1
S
1 c c 1 n c
1
1 1 n n
1
n n c R
L
Edge binding strengths: 1 2
n n
L
c R 1 c c c R 1 n c
1 L
n n n n 1 n c
1
1 c c n n c R
L
1 1 n n
1
n n 1 n c
1
n n n n c R
L L
n n n n n n 1 c c n n n n n n 1 n c
1
n n n n 1 1 n n
1
n n 1 c c 1 n c
1
n n n n 1 1 n n
1
n n 1 n c
1
1 1 n n
1
n n 1 1 n n
1
n n
What if the tiles cannot cooperate?
- The binding graph of an assembly is the grid graph
induced by tiles binding with positive strength.
Binding Graph
- The binding graph of an assembly is the grid graph
induced by tiles binding with positive strength.
Binding Graph
- The binding graph of an assembly is the grid graph
induced by tiles binding with positive strength.
- “Paths” in this talk always refer to paths in the binding
graph of some assembly.
Binding Graph
Self-Assembly at Temperature 1 Tiling the Plane
If tiles abut with matching kinds of (positive strength) glue, then they bind.
Tile set:
Self-Assembly at Temperature 1 Tiling the Plane
If tiles abut with matching kinds of (positive strength) glue, then they bind.
Tile set:
Self-Assembly at Temperature 1 Tiling the Plane
If tiles abut with matching kinds of (positive strength) glue, then they bind.
Tile set:
Self-Assembly at Temperature 1 Tiling the Plane
If tiles abut with matching kinds of (positive strength) glue, then they bind.
Tile set:
Self-Assembly at Temperature 1 Tiling the Plane
If tiles abut with matching kinds of (positive strength) glue, then they bind.
Tile set:
Self-Assembly at Temperature 1 Tiling the Plane
If tiles abut with matching kinds of (positive strength) glue, then they bind.
Tile set:
Self-Assembly at Temperature 1 Tiling the Plane
Self-Assembly at Temperature 1 Building a Periodic Line
1
S
2 1
2
Tile set:
1 2
1
1
S
Self-Assembly at Temperature 1 Building a Periodic Line
1
S
2 1
2
Tile set:
1 2
1
1
S
1 2
1
Self-Assembly at Temperature 1 Building a Periodic Line
1
S
2 1
2
Tile set:
1 2
1
1
S
2 1
2
1 2
1
Self-Assembly at Temperature 1 Building a Periodic Line
1
S
2 1
2
Tile set:
1 2
1
1
S
2 1
2
1 2
1
1 2
1
Self-Assembly at Temperature 1 Building a Periodic Line
1
S
2 1
2
Tile set:
1 2
1
1
S
2 1
2
1 2
1
2 1
2
1 2
1
Self-Assembly at Temperature 1 Building a Periodic Line
1
S
2 1
2
Tile set:
1 2
1
1
S
2 1
2
1 2
1
2 1
2
1 2
1
1 2
1
Self-Assembly at Temperature 1 Building a Periodic Line
1
S
2 1
2
Tile set:
1 2
1
1 2
1
1
S
2 1
2
1 2
1
2 1
2
1 2
1
1 2
1
2 1
2
2 1
2
1 2
1
1 2
1
2 1
2
2 1
2
1 2
1
1 2
1
2 1
2
2 1
2
1 2
1
1 2
1
2 1
2
2 1
2
1 2
1
1 2
1
2
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
3 4
3
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
3 4
3
3 1 2
1
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
3 4
3
4 3
4
3 1 2
1
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
3 4
3
4 3
4
3 1 2
1
2 1
2
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
3 4
3
4 3
4
3 1 2
1
2 1
2
3 4
3
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
3 4
3
4 3
4
3 4
3
3 1 2
1
2 1
2
3 4
3
Self-Assembly at Temperature 1 Building a “Comb”
1
S
2 1
2
3 1 2
1
3 4
3
4 3
4
Tile set:
1
S
3 1 2
1
2 1
2
3 4
3
4 3
4
3 4
3
3 1 2
1
2 1
2
3 4
3
4 3
4
1
S
3 1 2
1
2 1
2
3 4
3
4 3
4
3 4
3
4 3
4
3 1 2
1
2 1
2
3 1 2
1
2 1
2
3 1 2
1
2 1
2
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 1 2
1
2 1
2
3 1 2
1
2 1
2
3 1 2
1
2 1
2
3 1 2
1
2 1
2
3 1 2
1
2 1
2
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 1 2
1
2 1
2
3 1 1 3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
3 4
3
4 3
4
3 4
3
4 3
4
3 4
3
4 4 4 4 4 4 4 4 4 4 4
Self-Assembly at Temperature 1 Building a “Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building an “Eventual Comb”
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building a “Plane-Filling” Grid
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Self-Assembly at Temperature 1 Building A Complicated Structure
Our Result (Vaguely)
- The previous “complicated structure” intuitively
captures every set that can weakly self- assemble in a “nice” temperature 1 tile assembly system.
Our Result (Vaguely)
- The previous “complicated structure” intuitively
captures every set that can weakly self- assemble in a “nice” temperature 1 tile assembly system.
- Our proof relies on a notion of “pumpable
paths” in an assembly to define “nice”-ness.
Pumpability
Our result relies on a notion of pumpable paths in an assembly.
Pumpability
Our result relies on a notion of pumpable paths in an assembly. Partial assembly, with grey seed tile
Pumpability
“Sufficiently long” path Our result relies on a notion of pumpable paths in an assembly.
Pumpability
Our result relies on a notion of pumpable paths in an assembly. Look at just this partial path
Pumpability
Our result relies on a notion of pumpable paths in an assembly. Uniquely color each tile type
Pumpability
Our result relies on a notion of pumpable paths in an assembly. Note the repeating pattern, beginning with yellow tiles, which we call a pumpable segment
Pumpability
Our result relies on a notion of pumpable paths in an assembly. The pumpable segment can be infinitely repeated, or pumped, to create an infinite, periodic path
A “deterministic” (i.e., uniquely produces an assembly) temperature 1 tile assembly system T is c-pumpable if, given any two points p and q at least distance c apart in the terminal assembly of T, there is a path from p to q in the binding graph that contains a pumpable segment within the first c points on the path.
Pumpable Tile Assembly System
A “deterministic” (i.e., uniquely produces an assembly) temperature 1 tile assembly system T is c-pumpable if, given any two points p and q at least distance c apart in the terminal assembly of T, there is a path from p to q in the binding graph that contains a pumpable segment within the first c points on the path. In other words, every long path contains repetitions of a tile type (an obvious consequence of the pigeonhole principle) that can be pumped (repeated infinitely many times) to create a periodic path without colliding with the assembly up to that point.
Pumpable Tile Assembly System
Pumpability
Not all repeating patterns are pumpable!
Pumpability
Not all repeating patterns are pumpable!
Pumpability
Not all repeating patterns are pumpable!
Doubly Periodic Sets
The dark green tiles make up a doubly periodic set
A set of points is doubly periodic if every point in the set can be expressed as a nonnegative integer affine combination of two integer vectors:
Doubly Periodic Sets
An initial offset from the origin... base point b
The dark green tiles make up a doubly periodic set
A set of points is doubly periodic if every point in the set can be expressed as a nonnegative integer affine combination of two integer vectors:
Doubly Periodic Sets
An initial offset from the origin, plus a multiple of u... base point b
The dark green tiles make up a doubly periodic set
u
A set of points is doubly periodic if every point in the set can be expressed as a nonnegative integer affine combination of two integer vectors:
Doubly Periodic Sets
A set of points is doubly periodic if every point in the set can be expressed as a nonnegative integer affine combination of two integer vectors:
u v An initial offset from the origin, plus a multiple of u plus a multiple of v base point b
The dark green tiles make up a doubly periodic set
Doubly Periodic Sets
A set of points is doubly periodic if every point in the set can be expressed as a nonnegative integer affine combination of two integer vectors:
u An initial offset from the origin, plus a multiple of u plus a multiple of v The point b + 3u + 2v base point b
The dark green tiles make up a doubly periodic set
v
The Finite Closure of an Assembly
In our proof, we use the idea of a finite closure of a given (producible and non-terminal) assembly α.
The Finite Closure of an Assembly
In our proof, we use the idea of a finite closure of a given (producible and non-terminal) assembly α. Intuitively, if we extend α by only those “portions” that will eventually stop growing, the finite closure is the super- assembly that will be produced.
The Finite Closure of an Assembly
In our proof, we use the idea of a finite closure of a given (producible and non-terminal) assembly α. Intuitively, if we extend α by only those “portions” that will eventually stop growing, the finite closure is the super- assembly that will be produced. That is, any attempt to “leave” α through the finite closure and go infinitely far will eventually run into α again.
The Finite Closure of an Assembly
For example, consider the following (terminal) assembly.
The Finite Closure of an Assembly
For example, consider the following (terminal) assembly.
The Finite Closure of an Assembly
Consider the subassembly consisting of the dark red tiles...
The Finite Closure of an Assembly
Consider the subassembly consisting of the dark red tiles... The bottom row of the horizontal rectangle is incomplete, and all of the upward projections have yet to self-assemble.
The Finite Closure of an Assembly What is the finite closure this assembly?
The Finite Closure of an Assembly
It's the dark red tiles in this figure, because...
The Finite Closure of an Assembly
...a finite number of tiles can be added to each of these locations before they become terminal, but... It's the dark red tiles in this figure, because...
The Finite Closure of an Assembly
...a finite number of tiles can be added to each of these locations before they become terminal, but... ...an infinite number of tiles can be added to this location, so they are not on the finite closure. It's the dark red tiles in this figure, because...
The Finite Closure of an Assembly
The finite closure of an assembly is the "closure of the assembly under finite additions to a single frontier location." Formally, a point x is on the finite closure of an assembly α if every infinite path containing x in the terminal assembly intersects α.
Example x's in the finite closure
Main Result
- A subset X of the plane weakly self-assembles
in a finite tile assembly system if some of the tile types are colored “black,” and X consists of those points that eventually are tiled with a black tile.
Main Result
- A subset X of the plane weakly self-assembles
in a finite tile assembly system if some of the tile types are colored “black,” and X consists of those points that eventually are tiled with a black tile.
- Every set that weakly self-assembles in a
pumpable, deterministic, temperature 1 tile assembly system is a finite union of doubly periodic sets.
The Proof
- The finite closure of a periodic path or comb
defines a finite union of doubly periodic sets.
The Proof
- The finite closure of a periodic path or comb
defines a finite union of doubly periodic sets.
- There are only a finite number of periodic paths
and combs originating within a fixed radius around the origin.
The Proof
- The finite closure of a periodic path or comb
defines a finite union of doubly periodic sets.
- There are only a finite number of periodic paths
and combs originating within a fixed radius around the origin.
- We prove: If the tile system is c-pumpable, then
every black tile is on the finite closure of some periodic path, or comb, that originates within radius 2c of the origin.
The Proof (sketch)
seed seed
- 1. Pick a black tile
distance at least c from the origin.
The Proof (sketch)
seed seed
- 2. There is a pumpable
segment starting within radius c of the origin ...
- 1. Pick a black tile
distance at least c from the origin.
The Proof (sketch)
seed seed
- 2. There is a pumpable
segment starting within radius c of the origin ...
- 3. ...so this infinite periodic
path could happen instead.
- 1. Pick a black tile
distance at least c from the origin.
The Proof (sketch)
seed seed
- 3. ...so this infinite periodic
path could happen instead.
- 4. Maybe the black tile is on
the finite closure of the infinite periodic path. Done!
- 2. There is a pumpable
segment starting within radius c of the origin ...
- 1. Pick a black tile
distance at least c from the origin.
The Proof (sketch)
seed seed
- 4. Otherwise, another long
path that includes the first pumpable segment leads to the black tile.
- 2. There is a pumpable
segment starting within radius c of the origin ...
- 1. Pick a black tile
distance at least c from the origin.
The Proof (sketch)
seed seed
- 4. Otherwise, another long
path that includes the first pumpable segment leads to the black tile.
- 2. There is a pumpable
segment starting within radius c of the origin ...
- 1. Pick a black tile
distance at least c from the origin.
- 5. Another pumpable
segment...
The Proof (sketch)
seed seed
- 4. Otherwise, another long
path that includes the first pumpable segment leads to the black tile.
- 2. There is a pumpable
segment starting within radius c of the origin ...
- 1. Pick a black tile
distance at least c from the origin.
- 5. Another pumpable
segment... ...means more infinite periodic paths.
The Proof (sketch)
seed seed
- 4. Otherwise, another long
path that includes the first pumpable segment leads to the black tile.
- 2. There is a pumpable
segment starting within radius c of the origin ...
- 1. Pick a black tile
distance at least c from the origin.
- 5. Another pumpable
segment...
- 6. And we have a comb!
...means more infinite periodic paths.
The Proof (sketch)
The two vectors defining the comb form a basis for the region in which the black tile is contained, producing a regular array of parallelograms.
The Proof (sketch)
The two vectors defining the comb form a basis for the region in which the black tile is contained, producing a regular array of parallelograms. The “determinism” of the tile set enforces the same pattern in each parallelogram: a doubly periodic set.
The Proof (sketch)
There are a number of inaccuracies in the previous argument.
The Proof (sketch)
There are a number of inaccuracies in the previous argument.
But those would all result in this... A cycle intersecting two pumpable paths
The Proof (sketch)
There are a number of inaccuracies in the previous argument.
But those would all result in this... which we can prove results in this. A cycle intersecting two pumpable paths An infinite plane- covering grid
Conclusion
Informal thesis: if a computation can be performed with a tile assembly system, then the result of that computation can be represented as a set that weakly self-assembles in that system or a closely related system.
Conclusion
Informal thesis: If a computation can be performed with a tile assembly system, then the result of that computation can be represented as a set that weakly self-assembles in that system or a closely related system. Conclusion: Deterministic, pumpable, temperature 1 tile assembly systems are not capable of general-purpose computation.
Open Question
Conjecture: Every “deterministic” temperature 1 tile assembly system that produces an infinite assembly is pumpable.
Open Question
Conjecture: Every “deterministic” temperature 1 tile assembly system that produces an infinite assembly is pumpable. That is, no path can grow too far without growing
- ut of control (in a periodic manner) since the lack
- f cooperation inhibits controlled growth.
Open Question
Conjecture: Every “deterministic” temperature 1 tile assembly system that produces an infinite assembly is pumpable. That is, no path can grow too far without growing
- ut of control (in a periodic manner) since the lack
- f cooperation inhibits controlled growth.