\subsection{Motivation}
In recent years, computers are used to some extend in almost every industry in
Europe \cite{eurostat_ent_w_comp} and China \cite{iresearch_ent_w_comp}. This
leads to the conclusion, that also other countries must have a high usage of
computers in corporations. Furthermore, according to a statistic published by
\citeauthor{itu_hh_w_comp} in 2019, nearly half of the worldwide households have
access to at least one computer \cite{itu_hh_w_comp}. One of the most used
devices for data input while operating a computer is the keyboard
\parencite[22]{handbook_chi}. Therefore, people who use a computer, either at
home or to fulfill certain tasks at work, are also likely to use a keyboard. An
important part of a keyboard is the keyswitch also called keyboard key or
key. Those keyswitches use, depending on the manufacturer or keyboard type,
different mechanisms to actuate a keypress. More commonly used mechanism to date
are scissor switches, mostly used in laptop keyboards, rubber dome and membrane switches,
often used in low- to mid-priced keyboards, and mechanical switches which are
the main switch type for high-end and gaming keyboards
\cite{ergopedia_keyswitch}. Depending on the mechanism and type of key used, it
is possible that different force has to be applied to the key to activate
it. Normally, the force required to activate a key is identical for each key
across the keyboard. However, previous research has shown, that there is a
disparity in force generated by different fingers
\cite{bretz_finger_force}. This raises the question, why there are no keyboards
for personal or work related use cases with adjusted actuation forces per finger
or even customizable keyboards, where an individual can select the actuation
force for each keyswitch individually.

In recent decades, computers and other electronic devices have become an
indispensable part of everyday life. Computers are used in almost every industry
\cite{iresearch_ent_w_comp, eurostat_ent_w_comp} and almost half of the
worldwide households have access to at least one computer \cite{itu_hh_w_comp}.
Even 153 years after the first typewriter was patented \cite{noyes_qwerty, }
people still use keyboards as their main way to input data into a computer
\parencite[22]{handbook_chi}, \cite{broel_dektop_or_smartphone}. A potential
problem while interacting with a computer through the usage of a keyboard are
rapid movements of the fingers over a prolonged time.

Input tasks are not only restricted to pure data entry but also include complex
inputs required by games.


Prolonged usage of computers can lead to serious diseases



With the rising popularity of smartphones and other touchscreen devices
\cite{gs_statcounter_dmt_2020} which utilize virtual keyboards to fulfill a
variety of tasks that also include data entry, e.g., writing text messages,
short emails, communicating on social media or web browsing