Biological
Systems using biological substrates
Systems using Biological
Biological brain
general intelligence / perception, memory, reasoning, motor control
The human brain contains ~86 billion neurons connected by ~10¹⁵ synapses. Each neuron integrates thousands of synaptic inputs and fires a spike when its membrane potential crosses threshold — a leaky ...
DNA computer (Adleman 1994)
Hamiltonian path via strand hybridization
Leonard Adleman's 1994 demonstration solved the directed Hamiltonian path problem using DNA strand hybridization. Cities encoded as DNA sequences, flight connections as complementary strands. Massivel...
DNA strand-displacement computer
boolean logic / neural network inference (via hybridization cascades)
Single-stranded DNA molecules in solution compute via toehold-mediated strand displacement: a short single-stranded 'toehold' on a partially double-stranded gate complex allows an input strand to inva...
DishBrain (in-vitro neural culture)
closed-loop sensorimotor control / game-playing (via biological learning)
~800,000 human iPSC-derived or mouse cortical neurons are plated onto a high-density multi-electrode array (HD-MEA). The DishBrain system (Kagan et al., 2022, Neuron) embeds the culture in a simulated...
Physarum polycephalum (slime mold)
Steiner tree / shortest transport network (approximate)
The plasmodial slime mold extends filaments toward nutrient sources and progressively reinforces paths that carry more flow, pruning inefficient routes. Toshiyuki Nakagaki showed it reproduces the Tok...
Repressilator (synthetic gene oscillator)
limit-cycle oscillation / biological clock (via negative-feedback transcription loop)
Elowitz & Leibler (2000, Nature) constructed a synthetic oscillator in E. coli from three mutual repressor genes wired in a ring: LacI represses tetR; TetR represses cI; CI represses lacI. No gene pro...