Method for maskless patterning of metal alloys

A maskless method of making a metal surface comprising at least one hydrophobic region and at least one hydrophilic region, the method comprising:

• first treating at least one portion of a first major surface of a metal piece along a laser scan path to obtain a first treated surface;
• second treating the first treated surface with a composition comprising a hydrophobic surface modifier to obtain a hydrophobic first treated surface,
• third treating at least one portion of the hydrophobic first treated surface of the metal piece along a laser scan path to obtain a second treated surface;
• and
• fourth treating the second treated surface with a composition comprising a hydrophilic surface modifier to obtain a hydrophilic first treated surface;
• first treating at least one portion of a first major surface of a metal piece along a laser scan path to obtain a first treated surface;
• second treating the first treated surface with a composition comprising a hydrophilic surface modifier to obtain a hydrophilic first treated surface;
• third treating at least one portion of the hydrophilic first treated surface of the metal piece along a laser scan path to obtain a second treated surface;
• and
• fourth treating the second treated surface with a composition comprising a hydrophobic surface modifier to obtain a hydrophobic first treated surface;
• first treating at least one first portion of a first major surface of a metal piece along a laser scan path to obtain a first treated surface;
• second treating the first treated surface with a composition comprising a hydrophobic surface modifier to obtain a hydrophobic first treated surface;
• third treating at least a second portion of a first major surface of a metal piece along a laser scan path to obtain a second treated surface, the second portion different from the first portion;
• and
• fourth treating the second treated surface with a composition comprising a hydrophilic surface modifier to obtain a hydrophilic first treated surface;
• or
• first treating at least one first portion of a first major surface of a metal piece along a laser scan path to obtain a first treated surface;
• second treating the first treated surface with a composition comprising a hydrophilic surface modifier to obtain a hydrophilic first treated surface;
• third treating at least a second portion of a first major surface of a metal piece along a laser scan path to obtain a second treated surface, the second portion different from the first portion;
• and
• fourth treating the second treated surface with a composition comprising a hydrophobic surface modifier to obtain a hydrophobic first treated surface;
• wherein
• the hydrophilic surface modifier is a silane of the formula:
• X13SiR2
• wherein each X1 is halogen or a C1-C6-alkoxy group;
• and R2 is a C1-C6-cyano-substituted alkyl group.