Table of Contents

1. WEEK 1 (09/05-09/05): Brainstorming

1.1 The CBA version of a Telecaster? "The CBA Caster"

1.2 "Circular Economy Materials Lab of the Future?"

1.3 Fab Linear Capacitive Encoder?

1.4 A machine that is an analog of the ribosome? lol

1. WEEK1 (09/05-09/05): Final Project Brainstorming

1.1 The "CBA Caster"?

I always wanted to hack a Telecaster... The world's first commercially successful electric guitar! The physics of guitars is fascinating. Does the sound depend only on the materials and the pick ups? What is that magic element that allows the Telecaster to sound like a dream? What makes a Telecaster a good one? The good ones cost at least $2,000. Maybe I can make one with less than $500 and sound better.

1.2 "Circular Economy Materials Lab of the Future"

My mind keeps dribbling around the idea of fitting on a desktop a fully functional soft materials synthesis and characterization lab...This would require me to make one small machine/week. Too ambitious and too broad?

The ATOMS of the Materials Lab of the Future should have the following capabilities:
- should fit on a my CBA desktop
- hybrid materials synthesis - measurement - processing machines
- online metrology tools
The BITS of the Materials Lab of the Future should have the following capabilities:
- IoT (machine operation + monitoring + storing sensor data + mining data)
- physics-based simulation tools

The Materials Lab of the Future should have the following machines:

1.3 Cheap linear capacitive encoder?

Something that I heard about for the very first time form Neil. Cheap and simple absolute position sensing for linear actuators would be very useful. Digital calipers operate on this principle. I will learn a lot trying ot do that. I will come back to this idea after I do some simulations on capacitive sensing...

1.4 A machine that is an analog of the ribosome?

I know...I am stupid. Just writing down to remember these thoughts. This machine has to be extremely fast into assembling something that moves? Maybe a machine where the end effector is a droplet generator with extremely high droplet deposition frequency above a gantry? and inside the droplets the dispersed phase are hyper flagellated Ecoli bacteria??? and at the end I get a structure made form droplets that are stuck together and the encapsulated bacteria cause the whole structure to move? Non sense. I will think about it more.

I need to decide by this Sunday. Stop procrastinating. Stop thinking too much.

Overview of capacitive sensing

Capacitive sensors electronically measure the capacitance between 2 or more conductors in a dielectric environment usually air or liquid. A similar technique is electric field measurement, where the electrostatic voltage field produced by conductors in a dielectric environment is picked up by a probe and a high impedance amplifier. Spacing: If a metal object is near a capacitor electrode, teh coupling between the two is a very sensitive way to measure spacing. Shaft angle or linear position: Capacitive sensors can measure angle or position with a multiplate scheme giving high accuracy and digital output, or with an analog output with less absolute accuracy but simpler circuitry. Limit switch: Limit switches can detect the proximity of a metal machine component as an increase in capacitance, or the proximity of a plastic component by virtue of its increased dielectric constant over air.


Stray capacitance: Capacitance doesn't exist only within capacitors. In fact, any two surfaces at different electrical potential, and that are close enough together to generate an electric field , have capacitance and thus act like a capacitor. Such effects are often present within circuits -between conductive runs or component leads even though they are not intended. THis unintended capacitance is referred to as stray capacitance and it can result in disruption of normal flow within a current.


Multielectrode capacitors

Most discrfete capacitors used in electronics are 2-terminal devices, while most air-spaced cpacitors used for sensors have 3 or more terminals, with the added electrodes acting as shields or guards to control fringing flux, reduce unwanted stray capacitance, or shield against unwanted pickup of external electric fields.

Approximate Solutions

For most capacitive sensors designs, fringe capacitance and stray capacitance can be ignored or approximated without much trouble, but if max accuracy is needed, or if problems are encountered with capacitive crosstalk or strays, it is useful to have an analytical method as shown above to evaluate the capacitance of various electrode configurations. Usually it is inconvenient to measure the actual fringe or stray capacitance values, as the strays associated with the measuring equipment are much larger than the strays you are trying to measure. Calculating the strays is possible only for simple geometry with spatial symmetry in a given coordinate system. But an approximate solution is generally adequate; three options that give approximate solutions are field line sketches and finite element analysis.