Almost every laptop comes with a touchpad. However, the touchpad functions as an alternative to the mouse. It transforms the motion of the finger to the surface into a relative position of a cursor.
Touchpad only works with a finger with two methods. The first one is commonly used capacitive sensing where it senses any conducting properties which are our finger. It won’t work with a pencil or hands-wearing gloves.
The second one is conductive sensing where there are horizontal sets of wires and vertical sets of wires. When pressed the touchpad the wires get thinner and electricity is easily passed. The coordinates of the point of contact are now determined through this.
Why touchpad only allows the bare finger to work
Touchpads only allow the bare finger to work because naturally, the human body has conducting properties. It works on the principle of discharge.
The surface of the touchpad is positively charged and whenever you touch, from that point of contact, the charge flows out of your body as it is a good conductor of electricity.
How does the touchpad in a laptop detect a finger touch?
Touchpads in a laptop are two types resistive and capacitive. They detect touch using capacitance and conductance technology. Firstly, it’s important to know how resistive and capacitive touchpad work.
Resistive touchpads have a series of parallel wires and on top of that, have perpendicular wires. When an input is given, a matrix is produced. And when touched firmly, the coordinates determined the contact of the point.
The capacitive touchpad also has a series of matric similar to resistive but are not flexible. They have two parallel series of wires where a magnetic field is created. When a finger touches, a capacitor is formed and the magnetic field is changed. This change had been detected as the contact point.
Both resistive and capacitive use conductance and capacitance technology. Capacitance is the most popular and commonly used technology. It creates two arrays one is vertical and the other is horizontal. When you press the touchpad, the coordinates locate the touch.
Conductance is less common compared to capacitance. In Conductance, when you touch the top surface of the touchpad, pressure will be created at the bottom surface of the touchpad.
The sensor detects the touch and transforms it into a motion of the finger. This is how the touchpad in a laptop detects a finger touch.
What are the advantages of using a touchpad that allows only a bare finger?
The advantages of using a touchpad are:
- Easy to use.
- Portable to manage.
- Offers ergonomic support for handicapped.
- No need for installation if you have a built-in touchpad on your laptop.
- Touchpads are relatively fast.
- You don’t need to carry an extra device for your touchpad as it’s already compatible with your laptop.
What are the disadvantages of a touchpad that allows only a bare finger?
- Hard to use when a user has limited finger movement.
- Controlling the pointer is harder than using a mouse.
- Harder to use in cramped conditions as there is limited space to move.
- Prone to malfunction.
- There is a high probability of not working properly after multiple touching.
Verdict
Laptops have a built-in touchpad that only works with a bare finger. Your finger is a good conductor of electricity so by pressing the touchpad, electricity is flowing through the wires. Capacitance and conductance technology made it possible.